a class to store JSON values More...

#include <json.hpp>

Public Types
using	cbor_tag_handler_t = detail::cbor_tag_handler_t
	how to treat CBOR tags More...

using	error_handler_t = detail::error_handler_t
	how to treat decoding errors More...

using	initializer_list_t = std::initializer_list< detail::json_ref< basic_json >>
	helper type for initializer lists of basic_json values More...

using	input_format_t = detail::input_format_t

using	json_pointer = ::nlohmann::json_pointer< basic_json >
	JSON Pointer, see nlohmann::json_pointer. More...

using	json_sax_t = json_sax< basic_json >
	SAX interface type, see nlohmann::json_sax. More...

template<typename T , typename SFINAE >
using	json_serializer = JSONSerializer< T, SFINAE >

using	parse_event_t = detail::parse_event_t
	parser event types More...

using	parser_callback_t = detail::parser_callback_t< basic_json >
	per-element parser callback type More...

using	value_t = detail::value_t

Public Member Functions
JSON_HEDLEY_RETURNS_NON_NULL const char *	type_name () const noexcept
	return the type as string More...

Static Public Member Functions
static allocator_type	get_allocator ()
	returns the allocator associated with the container More...

static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json	meta ()
	returns version information on the library More...

Public Attributes
JSON_PRIVATE_UNLESS_TESTED	__pad3__: value_t m_type = value_t::null

json_value	m_value = {}
	the value of the current element More...

Private Types
using	basic_json_t = NLOHMANN_BASIC_JSON_TPL
	workaround type for MSVC More...

template<typename InputType >
using	binary_reader = ::nlohmann::detail::binary_reader< basic_json, InputType >

template<typename CharType >
using	binary_writer = ::nlohmann::detail::binary_writer< basic_json, CharType >

template<typename BasicJsonType >
using	internal_iterator = ::nlohmann::detail::internal_iterator< BasicJsonType >

template<typename BasicJsonType >
using	iter_impl = ::nlohmann::detail::iter_impl< BasicJsonType >

template<typename Iterator >
using	iteration_proxy = ::nlohmann::detail::iteration_proxy< Iterator >

template<typename Base >
using	json_reverse_iterator = ::nlohmann::detail::json_reverse_iterator< Base >

template<typename CharType >
using	output_adapter_t = ::nlohmann::detail::output_adapter_t< CharType >

using	primitive_iterator_t = ::nlohmann::detail::primitive_iterator_t

Private Member Functions
void	assert_invariant () const noexcept
	checks the class invariants More...

void	destroy (value_t t) noexcept

boolean_t	get_impl (boolean_t *) const
	get a boolean (explicit) More...

object_t *	get_impl_ptr (object_t *) noexcept
	get a pointer to the value (object) More...

constexpr const object_t *	get_impl_ptr (const object_t *) const noexcept
	get a pointer to the value (object) More...

array_t *	get_impl_ptr (array_t *) noexcept
	get a pointer to the value (array) More...

constexpr const array_t *	get_impl_ptr (const array_t *) const noexcept
	get a pointer to the value (array) More...

string_t *	get_impl_ptr (string_t *) noexcept
	get a pointer to the value (string) More...

constexpr const string_t *	get_impl_ptr (const string_t *) const noexcept
	get a pointer to the value (string) More...

boolean_t *	get_impl_ptr (boolean_t *) noexcept
	get a pointer to the value (boolean) More...

constexpr const boolean_t *	get_impl_ptr (const boolean_t *) const noexcept
	get a pointer to the value (boolean) More...

number_integer_t *	get_impl_ptr (number_integer_t *) noexcept
	get a pointer to the value (integer number) More...

constexpr const number_integer_t *	get_impl_ptr (const number_integer_t *) const noexcept
	get a pointer to the value (integer number) More...

number_unsigned_t *	get_impl_ptr (number_unsigned_t *) noexcept
	get a pointer to the value (unsigned number) More...

constexpr const number_unsigned_t *	get_impl_ptr (const number_unsigned_t *) const noexcept
	get a pointer to the value (unsigned number) More...

number_float_t *	get_impl_ptr (number_float_t *) noexcept
	get a pointer to the value (floating-point number) More...

constexpr const number_float_t *	get_impl_ptr (const number_float_t *) const noexcept
	get a pointer to the value (floating-point number) More...

binary_t *	get_impl_ptr (binary_t *) noexcept
	get a pointer to the value (binary) More...

constexpr const binary_t *	get_impl_ptr (const binary_t *) const noexcept
	get a pointer to the value (binary) More...

	json_value ()=default
	default constructor (for null values) More...

	json_value (boolean_t v) noexcept
	constructor for booleans More...

	json_value (number_integer_t v) noexcept
	constructor for numbers (integer) More...

	json_value (number_unsigned_t v) noexcept
	constructor for numbers (unsigned) More...

	json_value (number_float_t v) noexcept
	constructor for numbers (floating-point) More...

	json_value (value_t t)
	constructor for empty values of a given type More...

	json_value (const string_t &value)
	constructor for strings More...

	json_value (string_t &&value)
	constructor for rvalue strings More...

	json_value (const object_t &value)
	constructor for objects More...

	json_value (object_t &&value)
	constructor for rvalue objects More...

	json_value (const array_t &value)
	constructor for arrays More...

	json_value (array_t &&value)
	constructor for rvalue arrays More...

	json_value (const typename binary_t::container_type &value)
	constructor for binary arrays More...

	json_value (typename binary_t::container_type &&value)
	constructor for rvalue binary arrays More...

	json_value (const binary_t &value)
	constructor for binary arrays (internal type) More...

	json_value (binary_t &&value)
	constructor for rvalue binary arrays (internal type) More...

template<typename InputAdapterType >
static::nlohmann::detail::parser< basic_json, InputAdapterType >	parser (InputAdapterType adapter, detail::parser_callback_t< basic_json >cb=nullptr, const bool allow_exceptions=true, const bool ignore_comments=false)

Static Private Member Functions
template<typename T , typename... Args>
static JSON_HEDLEY_RETURNS_NON_NULL T *	create (Args &&...args)
	helper for exception-safe object creation More...

template<typename ReferenceType , typename ThisType >
static ReferenceType	get_ref_impl (ThisType &obj)
	helper function to implement get_ref() More...

Private Attributes
JSON_PRIVATE_UNLESS_TESTED	__pad0__: using lexer = ::nlohmann::detail::lexer_base<basic_json>

JSON_PRIVATE_UNLESS_TESTED	__pad1__: using serializer = ::nlohmann::detail::serializer<basic_json>

JSON_PRIVATE_UNLESS_TESTED	__pad2__: union json_value { object_t* object

array_t *	array
	array (stored with pointer to save storage) More...

binary_t *	binary
	binary (stored with pointer to save storage) More...

boolean_t	boolean
	boolean More...

number_float_t	number_float
	number (floating-point) More...

number_integer_t	number_integer
	number (integer) More...

number_unsigned_t	number_unsigned
	number (unsigned integer) More...

string_t *	string
	string (stored with pointer to save storage) More...

Friends
template<typename BasicJsonType , typename InputType , typename SAX >
class	::nlohmann::detail::binary_reader

template<typename BasicJsonType , typename CharType >
class	::nlohmann::detail::binary_writer

template<typename BasicJsonType >
class	::nlohmann::detail::iter_impl

template<typename BasicJsonType >
class	::nlohmann::detail::json_sax_dom_callback_parser

template<typename BasicJsonType >
class	::nlohmann::detail::json_sax_dom_parser

template<typename BasicJsonType , typename InputType >
class	::nlohmann::detail::parser

template<detail::value_t >
struct	detail::external_constructor

exceptions
Classes to implement user-defined exceptions.
using	exception = detail::exception
	general exception of the basic_json class More...

using	parse_error = detail::parse_error
	exception indicating a parse error More...

using	invalid_iterator = detail::invalid_iterator
	exception indicating errors with iterators More...

using	type_error = detail::type_error
	exception indicating executing a member function with a wrong type More...

using	out_of_range = detail::out_of_range
	exception indicating access out of the defined range More...

using	other_error = detail::other_error
	exception indicating other library errors More...

container types
The canonic container types to use basic_json like any other STL container.
using	value_type = basic_json
	the type of elements in a basic_json container More...

using	reference = value_type &
	the type of an element reference More...

using	const_reference = const value_type &
	the type of an element const reference More...

using	difference_type = std::ptrdiff_t
	a type to represent differences between iterators More...

using	size_type = std::size_t
	a type to represent container sizes More...

using	allocator_type = AllocatorType< basic_json >
	the allocator type More...

using	pointer = typename std::allocator_traits< allocator_type >::pointer
	the type of an element pointer More...

using	const_pointer = typename std::allocator_traits< allocator_type >::const_pointer
	the type of an element const pointer More...

using	iterator = iter_impl< basic_json >
	an iterator for a basic_json container More...

using	const_iterator = iter_impl< const basic_json >
	a const iterator for a basic_json container More...

using	reverse_iterator = json_reverse_iterator< typename basic_json::iterator >
	a reverse iterator for a basic_json container More...

using	const_reverse_iterator = json_reverse_iterator< typename basic_json::const_iterator >
	a const reverse iterator for a basic_json container More...

JSON value data types
The data types to store a JSON value. These types are derived from the template arguments passed to class basic_json.
using	object_comparator_t = std::less< StringType >

using	object_t = ObjectType< StringType, basic_json, object_comparator_t, AllocatorType< std::pair< const StringType, basic_json >>>
	a type for an object More...

using	array_t = ArrayType< basic_json, AllocatorType< basic_json >>
	a type for an array More...

using	string_t = StringType
	a type for a string More...

using	boolean_t = BooleanType
	a type for a boolean More...

using	number_integer_t = NumberIntegerType
	a type for a number (integer) More...

using	number_unsigned_t = NumberUnsignedType
	a type for a number (unsigned) More...

using	number_float_t = NumberFloatType
	a type for a number (floating-point) More...

using	binary_t = nlohmann::byte_container_with_subtype< BinaryType >
	a type for a packed binary type More...

constructors and destructors
Constructors of class basic_json, copy/move constructor, copy assignment, static functions creating objects, and the destructor.
static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json	binary (const typename binary_t::container_type &init)
	explicitly create a binary array (without subtype) More...

static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json	binary (const typename binary_t::container_type &init, std::uint8_t subtype)
	explicitly create a binary array (with subtype) More...

static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json	binary (typename binary_t::container_type &&init)
	explicitly create a binary array (without subtype) More...

static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json	binary (typename binary_t::container_type &&init, std::uint8_t subtype)
	explicitly create a binary array (with subtype) More...

static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json	array (initializer_list_t init={})
	explicitly create an array from an initializer list More...

static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json	object (initializer_list_t init={})
	explicitly create an object from an initializer list More...

	basic_json (const value_t v)
	create an empty value with a given type More...

	basic_json (std::nullptr_t=nullptr) noexcept
	create a null object More...

template<typename CompatibleType , typename U = detail::uncvref_t<CompatibleType>, detail::enable_if_t< !detail::is_basic_json< U >::value &&detail::is_compatible_type< basic_json_t, U >::value, int > = 0>
	basic_json (CompatibleType &&val) noexcept(noexcept(JSONSerializer< U >::to_json(std::declval< basic_json_t & >(), std::forward< CompatibleType >(val))))
	create a JSON value More...

template<typename BasicJsonType , detail::enable_if_t< detail::is_basic_json< BasicJsonType >::value &&!std::is_same< basic_json, BasicJsonType >::value, int > = 0>
	basic_json (const BasicJsonType &val)
	create a JSON value from an existing one More...

	basic_json (initializer_list_t init, bool type_deduction=true, value_t manual_type=value_t::array)
	create a container (array or object) from an initializer list More...

	basic_json (size_type cnt, const basic_json &val)
	construct an array with count copies of given value More...

template<class InputIT , typename std::enable_if< std::is_same< InputIT, typename basic_json_t::iterator >::value\|\|std::is_same< InputIT, typename basic_json_t::const_iterator >::value, int >::type = 0>
	basic_json (InputIT first, InputIT last)
	construct a JSON container given an iterator range More...

template<typename JsonRef , detail::enable_if_t< detail::conjunction< detail::is_json_ref< JsonRef >, std::is_same< typename JsonRef::value_type, basic_json >>::value, int > = 0>
	basic_json (const JsonRef &ref)

	basic_json (const basic_json &other)
	copy constructor More...

	basic_json (basic_json &&other) noexcept
	move constructor More...

basic_json &	operator= (basic_json other) noexcept(std::is_nothrow_move_constructible< value_t >::value &&std::is_nothrow_move_assignable< value_t >::value &&std::is_nothrow_move_constructible< json_value >::value &&std::is_nothrow_move_assignable< json_value >::value)
	copy assignment More...

	~basic_json () noexcept
	destructor More...

object inspection
Functions to inspect the type of a JSON value.
string_t	dump (const int indent=-1, const char indent_char= ' ', const bool ensure_ascii=false, const error_handler_t error_handler=error_handler_t::strict) const
	serialization More...

constexpr value_t	type () const noexcept
	return the type of the JSON value (explicit) More...

constexpr bool	is_primitive () const noexcept
	return whether type is primitive More...

constexpr bool	is_structured () const noexcept
	return whether type is structured More...

constexpr bool	is_null () const noexcept
	return whether value is null More...

constexpr bool	is_boolean () const noexcept
	return whether value is a boolean More...

constexpr bool	is_number () const noexcept
	return whether value is a number More...

constexpr bool	is_number_integer () const noexcept
	return whether value is an integer number More...

constexpr bool	is_number_unsigned () const noexcept
	return whether value is an unsigned integer number More...

constexpr bool	is_number_float () const noexcept
	return whether value is a floating-point number More...

constexpr bool	is_object () const noexcept
	return whether value is an object More...

constexpr bool	is_array () const noexcept
	return whether value is an array More...

constexpr bool	is_string () const noexcept
	return whether value is a string More...

constexpr bool	is_binary () const noexcept
	return whether value is a binary array More...

constexpr bool	is_discarded () const noexcept
	return whether value is discarded More...

constexpr	operator value_t () const noexcept
	return the type of the JSON value (implicit) More...

value access
Direct access to the stored value of a JSON value.
template<typename BasicJsonType , detail::enable_if_t< std::is_same< typename std::remove_const< BasicJsonType >::type, basic_json_t >::value, int > = 0>
basic_json	get () const
	get special-case overload More...

template<typename BasicJsonType , detail::enable_if_t< !std::is_same< BasicJsonType, basic_json >::value &&detail::is_basic_json< BasicJsonType >::value, int > = 0>
BasicJsonType	get () const
	get special-case overload More...

template<typename ValueTypeCV , typename ValueType = detail::uncvref_t<ValueTypeCV>, detail::enable_if_t< !detail::is_basic_json< ValueType >::value &&detail::has_from_json< basic_json_t, ValueType >::value &&!detail::has_non_default_from_json< basic_json_t, ValueType >::value, int > = 0>
ValueType	get () const noexcept(noexcept(JSONSerializer< ValueType >::from_json(std::declval< const basic_json_t & >(), std::declval< ValueType & >())))
	get a value (explicit) More...

template<typename ValueTypeCV , typename ValueType = detail::uncvref_t<ValueTypeCV>, detail::enable_if_t< !std::is_same< basic_json_t, ValueType >::value &&detail::has_non_default_from_json< basic_json_t, ValueType >::value, int > = 0>
ValueType	get () const noexcept(noexcept(JSONSerializer< ValueType >::from_json(std::declval< const basic_json_t & >())))
	get a value (explicit); special case More...

template<typename ValueType , detail::enable_if_t< !detail::is_basic_json< ValueType >::value &&detail::has_from_json< basic_json_t, ValueType >::value, int > = 0>
ValueType &	get_to (ValueType &v) const noexcept(noexcept(JSONSerializer< ValueType >::from_json(std::declval< const basic_json_t & >(), v)))
	get a value (explicit) More...

template<typename ValueType , detail::enable_if_t< detail::is_basic_json< ValueType >::value, int > = 0>
ValueType &	get_to (ValueType &v) const

template<typename T , std::size_t N, typename Array = T (&)[N], detail::enable_if_t< detail::has_from_json< basic_json_t, Array >::value, int > = 0>
Array	get_to (T(&v)[N]) const noexcept(noexcept(JSONSerializer< Array >::from_json(std::declval< const basic_json_t & >(), v)))

template<typename PointerType , typename std::enable_if< std::is_pointer< PointerType >::value, int >::type = 0>
auto	get_ptr () noexcept-> decltype(std::declval< basic_json_t & >().get_impl_ptr(std::declval< PointerType >()))
	get a pointer value (implicit) More...

template<typename PointerType , typename std::enable_if< std::is_pointer< PointerType >::value &&std::is_const< typename std::remove_pointer< PointerType >::type >::value, int >::type = 0>
constexpr auto	get_ptr () const noexcept-> decltype(std::declval< const basic_json_t & >().get_impl_ptr(std::declval< PointerType >()))
	get a pointer value (implicit) More...

template<typename PointerType , typename std::enable_if< std::is_pointer< PointerType >::value, int >::type = 0>
auto	get () noexcept-> decltype(std::declval< basic_json_t & >().template get_ptr< PointerType >())
	get a pointer value (explicit) More...

template<typename PointerType , typename std::enable_if< std::is_pointer< PointerType >::value, int >::type = 0>
constexpr auto	get () const noexcept-> decltype(std::declval< const basic_json_t & >().template get_ptr< PointerType >())
	get a pointer value (explicit) More...

template<typename ReferenceType , typename std::enable_if< std::is_reference< ReferenceType >::value, int >::type = 0>
ReferenceType	get_ref ()
	get a reference value (implicit) More...

template<typename ReferenceType , typename std::enable_if< std::is_reference< ReferenceType >::value &&std::is_const< typename std::remove_reference< ReferenceType >::type >::value, int >::type = 0>
ReferenceType	get_ref () const
	get a reference value (implicit) More...

template<typename ValueType , typename std::enable_if< !std::is_pointer< ValueType >::value &&!std::is_same< ValueType, detail::json_ref< basic_json >>::value &&!std::is_same< ValueType, typename string_t::value_type >::value &&!detail::is_basic_json< ValueType >::value &&!std::is_same< ValueType, std::initializer_list< typename string_t::value_type >>::value &&detail::is_detected< detail::get_template_function, const basic_json_t &, ValueType >::value, int >::type = 0>
JSON_EXPLICIT	operator ValueType () const
	get a value (implicit) More...

binary_t &	get_binary ()

const binary_t &	get_binary () const

element access
Access to the JSON value.
reference	at (size_type idx)
	access specified array element with bounds checking More...

const_reference	at (size_type idx) const
	access specified array element with bounds checking More...

reference	at (const typename object_t::key_type &key)
	access specified object element with bounds checking More...

const_reference	at (const typename object_t::key_type &key) const
	access specified object element with bounds checking More...

reference	operator[] (size_type idx)
	access specified array element More...

const_reference	operator[] (size_type idx) const
	access specified array element More...

reference	operator[] (const typename object_t::key_type &key)
	access specified object element More...

const_reference	operator[] (const typename object_t::key_type &key) const
	read-only access specified object element More...

template<typename T >
reference	operator[] (T *key)
	access specified object element More...

template<typename T >
const_reference	operator[] (T *key) const
	read-only access specified object element More...

template<class ValueType , typename std::enable_if< detail::is_getable< basic_json_t, ValueType >::value &&!std::is_same< value_t, ValueType >::value, int >::type = 0>
ValueType	value (const typename object_t::key_type &key, const ValueType &default_value) const
	access specified object element with default value More...

string_t	value (const typename object_t::key_type &key, const char *default_value) const
	overload for a default value of type const char* More...

template<class ValueType , typename std::enable_if< detail::is_getable< basic_json_t, ValueType >::value, int >::type = 0>
ValueType	value (const json_pointer &ptr, const ValueType &default_value) const
	access specified object element via JSON Pointer with default value More...

string_t	value (const json_pointer &ptr, const char *default_value) const
	overload for a default value of type const char* More...

reference	front ()
	access the first element More...

const_reference	front () const
	access the first element More...

reference	back ()
	access the last element More...

const_reference	back () const
	access the last element More...

template<class IteratorType , typename std::enable_if< std::is_same< IteratorType, typename basic_json_t::iterator >::value\|\|std::is_same< IteratorType, typename basic_json_t::const_iterator >::value, int >::type = 0>
IteratorType	erase (IteratorType pos)
	remove element given an iterator More...

template<class IteratorType , typename std::enable_if< std::is_same< IteratorType, typename basic_json_t::iterator >::value\|\|std::is_same< IteratorType, typename basic_json_t::const_iterator >::value, int >::type = 0>
IteratorType	erase (IteratorType first, IteratorType last)
	remove elements given an iterator range More...

size_type	erase (const typename object_t::key_type &key)
	remove element from a JSON object given a key More...

void	erase (const size_type idx)
	remove element from a JSON array given an index More...

lookup
template<typename KeyT >
iterator	find (KeyT &&key)
	find an element in a JSON object More...

template<typename KeyT >
const_iterator	find (KeyT &&key) const
	find an element in a JSON object More...

template<typename KeyT >
size_type	count (KeyT &&key) const
	returns the number of occurrences of a key in a JSON object More...

template<typename KeyT , typename std::enable_if< !std::is_same< typename std::decay< KeyT >::type, json_pointer >::value, int >::type = 0>
bool	contains (KeyT &&key) const
	check the existence of an element in a JSON object More...

bool	contains (const json_pointer &ptr) const
	check the existence of an element in a JSON object given a JSON pointer More...

iterators
static iteration_proxy< iterator >	iterator_wrapper (reference ref) noexcept
	wrapper to access iterator member functions in range-based for More...

static iteration_proxy< const_iterator >	iterator_wrapper (const_reference ref) noexcept
	wrapper to access iterator member functions in range-based for More...

iterator	begin () noexcept
	returns an iterator to the first element More...

const_iterator	begin () const noexcept
	returns a const iterator to the first element More...

const_iterator	cbegin () const noexcept
	returns a const iterator to the first element More...

iterator	end () noexcept
	returns an iterator to one past the last element More...

const_iterator	end () const noexcept
	returns a const iterator to one past the last element More...

const_iterator	cend () const noexcept
	returns a const iterator to one past the last element More...

reverse_iterator	rbegin () noexcept
	returns an iterator to the reverse-beginning More...

const_reverse_iterator	rbegin () const noexcept
	returns a const reverse iterator to the last element More...

reverse_iterator	rend () noexcept
	returns an iterator to the reverse-end More...

const_reverse_iterator	rend () const noexcept
	returns a const reverse iterator to one before the first More...

const_reverse_iterator	crbegin () const noexcept
	returns a const reverse iterator to the last element More...

const_reverse_iterator	crend () const noexcept
	returns a const reverse iterator to one before the first More...

iteration_proxy< iterator >	items () noexcept
	helper to access iterator member functions in range-based for More...

iteration_proxy< const_iterator >	items () const noexcept
	helper to access iterator member functions in range-based for More...

capacity
bool	empty () const noexcept
	checks whether the container is empty. More...

size_type	size () const noexcept
	returns the number of elements More...

size_type	max_size () const noexcept
	returns the maximum possible number of elements More...

modifiers
void	swap (reference left, reference right) noexcept(std::is_nothrow_move_constructible< value_t >::value &&std::is_nothrow_move_assignable< value_t >::value &&std::is_nothrow_move_constructible< json_value >::value &&std::is_nothrow_move_assignable< json_value >::value)
	exchanges the values More...

void	clear () noexcept
	clears the contents More...

void	push_back (basic_json &&val)
	add an object to an array More...

reference	operator+= (basic_json &&val)
	add an object to an array More...

void	push_back (const basic_json &val)
	add an object to an array More...

reference	operator+= (const basic_json &val)
	add an object to an array More...

void	push_back (const typename object_t::value_type &val)
	add an object to an object More...

reference	operator+= (const typename object_t::value_type &val)
	add an object to an object More...

void	push_back (initializer_list_t init)
	add an object to an object More...

reference	operator+= (initializer_list_t init)
	add an object to an object More...

template<class... Args>
reference	emplace_back (Args &&...args)
	add an object to an array More...

template<class... Args>
std::pair< iterator, bool >	emplace (Args &&...args)
	add an object to an object if key does not exist More...

template<typename... Args>
iterator	insert_iterator (const_iterator pos, Args &&...args)

iterator	insert (const_iterator pos, const basic_json &val)
	inserts element More...

iterator	insert (const_iterator pos, basic_json &&val)
	inserts element More...

iterator	insert (const_iterator pos, size_type cnt, const basic_json &val)
	inserts elements More...

iterator	insert (const_iterator pos, const_iterator first, const_iterator last)
	inserts elements More...

iterator	insert (const_iterator pos, initializer_list_t ilist)
	inserts elements More...

void	insert (const_iterator first, const_iterator last)
	inserts elements More...

void	update (const_reference j)
	updates a JSON object from another object, overwriting existing keys More...

void	update (const_iterator first, const_iterator last)
	updates a JSON object from another object, overwriting existing keys More...

void	swap (reference other) noexcept(std::is_nothrow_move_constructible< value_t >::value &&std::is_nothrow_move_assignable< value_t >::value &&std::is_nothrow_move_constructible< json_value >::value &&std::is_nothrow_move_assignable< json_value >::value)
	exchanges the values More...

void	swap (array_t &other)
	exchanges the values More...

void	swap (object_t &other)
	exchanges the values More...

void	swap (string_t &other)
	exchanges the values More...

void	swap (binary_t &other)
	exchanges the values More...

void	swap (typename binary_t::container_type &other)

lexicographical comparison operators
bool	operator== (const_reference lhs, const_reference rhs) noexcept
	comparison: equal More...

template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>
bool	operator== (const_reference lhs, const ScalarType rhs) noexcept
	comparison: equal More...

template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>
bool	operator== (const ScalarType lhs, const_reference rhs) noexcept
	comparison: equal More...

bool	operator!= (const_reference lhs, const_reference rhs) noexcept
	comparison: not equal More...

template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>
bool	operator!= (const_reference lhs, const ScalarType rhs) noexcept
	comparison: not equal More...

template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>
bool	operator!= (const ScalarType lhs, const_reference rhs) noexcept
	comparison: not equal More...

bool	operator< (const_reference lhs, const_reference rhs) noexcept
	comparison: less than More...

template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>
bool	operator< (const_reference lhs, const ScalarType rhs) noexcept
	comparison: less than More...

template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>
bool	operator< (const ScalarType lhs, const_reference rhs) noexcept
	comparison: less than More...

bool	operator<= (const_reference lhs, const_reference rhs) noexcept
	comparison: less than or equal More...

template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>
bool	operator<= (const_reference lhs, const ScalarType rhs) noexcept
	comparison: less than or equal More...

template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>
bool	operator<= (const ScalarType lhs, const_reference rhs) noexcept
	comparison: less than or equal More...

bool	operator> (const_reference lhs, const_reference rhs) noexcept
	comparison: greater than More...

template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>
bool	operator> (const_reference lhs, const ScalarType rhs) noexcept
	comparison: greater than More...

template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>
bool	operator> (const ScalarType lhs, const_reference rhs) noexcept
	comparison: greater than More...

bool	operator>= (const_reference lhs, const_reference rhs) noexcept
	comparison: greater than or equal More...

template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>
bool	operator>= (const_reference lhs, const ScalarType rhs) noexcept
	comparison: greater than or equal More...

template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>
bool	operator>= (const ScalarType lhs, const_reference rhs) noexcept
	comparison: greater than or equal More...

serialization
std::ostream &	operator<< (std::ostream &o, const basic_json &j)
	serialize to stream More...

std::ostream &	operator>> (const basic_json &j, std::ostream &o)
	serialize to stream More...

deserialization
std::istream &	operator<< (basic_json &j, std::istream &i)
	deserialize from stream More...

std::istream &	operator>> (std::istream &i, basic_json &j)
	deserialize from stream More...

template<typename InputType >
static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json	parse (InputType &&i, const parser_callback_t cb=nullptr, const bool allow_exceptions=true, const bool ignore_comments=false)
	deserialize from a compatible input More...

template<typename IteratorType >
static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json	parse (IteratorType first, IteratorType last, const parser_callback_t cb=nullptr, const bool allow_exceptions=true, const bool ignore_comments=false)
	deserialize from a pair of character iterators More...

static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json	parse (detail::span_input_adapter &&i, const parser_callback_t cb=nullptr, const bool allow_exceptions=true, const bool ignore_comments=false)

template<typename InputType >
static bool	accept (InputType &&i, const bool ignore_comments=false)
	check if the input is valid JSON More...

template<typename IteratorType >
static bool	accept (IteratorType first, IteratorType last, const bool ignore_comments=false)

static JSON_HEDLEY_WARN_UNUSED_RESULT bool	accept (detail::span_input_adapter &&i, const bool ignore_comments=false)

template<typename InputType , typename SAX >
static bool	sax_parse (InputType &&i, SAX *sax, input_format_t format=input_format_t::json, const bool strict=true, const bool ignore_comments=false)
	generate SAX events More...

template<class IteratorType , class SAX >
static bool	sax_parse (IteratorType first, IteratorType last, SAX *sax, input_format_t format=input_format_t::json, const bool strict=true, const bool ignore_comments=false)

template<typename SAX >
static bool	sax_parse (detail::span_input_adapter &&i, SAX *sax, input_format_t format=input_format_t::json, const bool strict=true, const bool ignore_comments=false)

binary serialization/deserialization support
static std::vector< uint8_t >	to_cbor (const basic_json &j)
	create a CBOR serialization of a given JSON value More...

static void	to_cbor (const basic_json &j, detail::output_adapter< uint8_t > o)

static void	to_cbor (const basic_json &j, detail::output_adapter< char > o)

static std::vector< uint8_t >	to_msgpack (const basic_json &j)
	create a MessagePack serialization of a given JSON value More...

static void	to_msgpack (const basic_json &j, detail::output_adapter< uint8_t > o)

static void	to_msgpack (const basic_json &j, detail::output_adapter< char > o)

static std::vector< uint8_t >	to_ubjson (const basic_json &j, const bool use_size=false, const bool use_type=false)
	create a UBJSON serialization of a given JSON value More...

static void	to_ubjson (const basic_json &j, detail::output_adapter< uint8_t > o, const bool use_size=false, const bool use_type=false)

static void	to_ubjson (const basic_json &j, detail::output_adapter< char > o, const bool use_size=false, const bool use_type=false)

static std::vector< uint8_t >	to_bson (const basic_json &j)
	Serializes the given JSON object `j` to BSON and returns a vector containing the corresponding BSON-representation. More...

static void	to_bson (const basic_json &j, detail::output_adapter< uint8_t > o)
	Serializes the given JSON object `j` to BSON and forwards the corresponding BSON-representation to the given output_adapter `o`. More...

static void	to_bson (const basic_json &j, detail::output_adapter< char > o)
	Serializes the given JSON object `j` to BSON and forwards the corresponding BSON-representation to the given output_adapter `o`. More...

template<typename InputType >
static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json	from_cbor (InputType &&i, const bool strict=true, const bool allow_exceptions=true, const cbor_tag_handler_t tag_handler=cbor_tag_handler_t::error)
	create a JSON value from an input in CBOR format More...

template<typename IteratorType >
static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json	from_cbor (IteratorType first, IteratorType last, const bool strict=true, const bool allow_exceptions=true, const cbor_tag_handler_t tag_handler=cbor_tag_handler_t::error)

template<typename T >
static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json	from_cbor (const T *ptr, std::size_t len, const bool strict=true, const bool allow_exceptions=true, const cbor_tag_handler_t tag_handler=cbor_tag_handler_t::error)

static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json	from_cbor (detail::span_input_adapter &&i, const bool strict=true, const bool allow_exceptions=true, const cbor_tag_handler_t tag_handler=cbor_tag_handler_t::error)

template<typename InputType >
static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json	from_msgpack (InputType &&i, const bool strict=true, const bool allow_exceptions=true)
	create a JSON value from an input in MessagePack format More...

template<typename IteratorType >
static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json	from_msgpack (IteratorType first, IteratorType last, const bool strict=true, const bool allow_exceptions=true)

template<typename T >
static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json	from_msgpack (const T *ptr, std::size_t len, const bool strict=true, const bool allow_exceptions=true)

static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json	from_msgpack (detail::span_input_adapter &&i, const bool strict=true, const bool allow_exceptions=true)

template<typename InputType >
static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json	from_ubjson (InputType &&i, const bool strict=true, const bool allow_exceptions=true)
	create a JSON value from an input in UBJSON format More...

template<typename IteratorType >
static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json	from_ubjson (IteratorType first, IteratorType last, const bool strict=true, const bool allow_exceptions=true)

template<typename T >
static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json	from_ubjson (const T *ptr, std::size_t len, const bool strict=true, const bool allow_exceptions=true)

static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json	from_ubjson (detail::span_input_adapter &&i, const bool strict=true, const bool allow_exceptions=true)

template<typename InputType >
static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json	from_bson (InputType &&i, const bool strict=true, const bool allow_exceptions=true)
	Create a JSON value from an input in BSON format. More...

template<typename IteratorType >
static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json	from_bson (IteratorType first, IteratorType last, const bool strict=true, const bool allow_exceptions=true)

template<typename T >
static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json	from_bson (const T *ptr, std::size_t len, const bool strict=true, const bool allow_exceptions=true)

static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json	from_bson (detail::span_input_adapter &&i, const bool strict=true, const bool allow_exceptions=true)

JSON Pointer functions
reference	operator[] (const json_pointer &ptr)
	access specified element via JSON Pointer More...

const_reference	operator[] (const json_pointer &ptr) const
	access specified element via JSON Pointer More...

reference	at (const json_pointer &ptr)
	access specified element via JSON Pointer More...

const_reference	at (const json_pointer &ptr) const
	access specified element via JSON Pointer More...

basic_json	flatten () const
	return flattened JSON value More...

basic_json	unflatten () const
	unflatten a previously flattened JSON value More...

JSON Patch functions
static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json	diff (const basic_json &source, const basic_json &target, const std::string &path="")
	creates a diff as a JSON patch More...

basic_json	patch (const basic_json &json_patch) const
	applies a JSON patch More...

JSON Merge Patch functions
void	merge_patch (const basic_json &apply_patch)
	applies a JSON Merge Patch More...

Detailed Description

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>
class nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >

a class to store JSON values

Template Parameters

ObjectType	type for JSON objects (`std::map` by default; will be used in object_t)
ArrayType	type for JSON arrays (`std::vector` by default; will be used in array_t)
StringType	type for JSON strings and object keys (`std::string` by default; will be used in string_t)
BooleanType	type for JSON booleans (`bool` by default; will be used in boolean_t)
NumberIntegerType	type for JSON integer numbers (`int64_t` by default; will be used in number_integer_t)
NumberUnsignedType	type for JSON unsigned integer numbers (`uint64_t` by default; will be used in number_unsigned_t)
NumberFloatType	type for JSON floating-point numbers (`double` by default; will be used in number_float_t)
BinaryType	type for packed binary data for compatibility with binary serialization formats (`std::vector<std::uint8_t>` by default; will be used in binary_t)
AllocatorType	type of the allocator to use (`std::allocator` by default)
JSONSerializer	the serializer to resolve internal calls to `to_json()` and `from_json()` (adl_serializer by default)

The class satisfies the following concept requirements:

Basic
- DefaultConstructible: JSON values can be default constructed. The result will be a JSON null value.
- MoveConstructible: A JSON value can be constructed from an rvalue argument.
- CopyConstructible: A JSON value can be copy-constructed from an lvalue expression.
- MoveAssignable: A JSON value van be assigned from an rvalue argument.
- CopyAssignable: A JSON value can be copy-assigned from an lvalue expression.
- Destructible: JSON values can be destructed.
Layout
- StandardLayoutType: JSON values have standard layout: All non-static data members are private and standard layout types, the class has no virtual functions or (virtual) base classes.
Library-wide
- EqualityComparable: JSON values can be compared with ==, see operator==(const_reference,const_reference).
- LessThanComparable: JSON values can be compared with <, see operator<(const_reference,const_reference).
- Swappable: Any JSON lvalue or rvalue of can be swapped with any lvalue or rvalue of other compatible types, using unqualified function call swap().
- NullablePointer: JSON values can be compared against std::nullptr_t objects which are used to model the null value.
Container
- Container: JSON values can be used like STL containers and provide iterator access.
- ReversibleContainer; JSON values can be used like STL containers and provide reverse iterator access.

Invariant

The member variables m_value and m_type have the following relationship:

If m_type == value_t::object, then m_value.object != nullptr.
If m_type == value_t::array, then m_value.array != nullptr.
If m_type == value_t::string, then m_value.string != nullptr. The invariants are checked by member function assert_invariant().

See also: RFC 7159: The JavaScript Object Notation (JSON) Data Interchange Format

Since: version 1.0.0

Definition at line 2976 of file json.hpp.

Member Typedef Documentation

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::allocator_type = AllocatorType<basic_json>

the allocator type

Definition at line 16858 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::array_t = ArrayType<basic_json, AllocatorType<basic_json>>

a type for an array

RFC 7159 describes JSON arrays as follows:

An array is an ordered sequence of zero or more values.

To store objects in C++, a type is defined by the template parameters explained below.

Template Parameters

ArrayType	container type to store arrays (e.g., `std::vector` or `std::list`)
AllocatorType	allocator to use for arrays (e.g., `std::allocator`)

Default type

With the default values for ArrayType (std::vector) and AllocatorType (std::allocator), the default value for array_t is:

std::vector<
  basic_json, // value_type
  std::allocator<basic_json> // allocator_type
>

Limits

RFC 7159 specifies:

An implementation may set limits on the maximum depth of nesting.

In this class, the array's limit of nesting is not explicitly constrained. However, a maximum depth of nesting may be introduced by the compiler or runtime environment. A theoretical limit can be queried by calling the max_size function of a JSON array.

Storage

Arrays are stored as pointers in a basic_json type. That is, for any access to array values, a pointer of type array_t* must be dereferenced.

See also: object_t – type for an object value

Since: version 1.0.0

Definition at line 17118 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::basic_json_t = NLOHMANN_BASIC_JSON_TPL

private

workaround type for MSVC

Definition at line 16756 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename InputType >

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::binary_reader = ::nlohmann::detail::binary_reader<basic_json, InputType>

private

Definition at line 16788 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::binary_t = nlohmann::byte_container_with_subtype<BinaryType>

a type for a packed binary type

This type is a type designed to carry binary data that appears in various serialized formats, such as CBOR's Major Type 2, MessagePack's bin, and BSON's generic binary subtype. This type is NOT a part of standard JSON and exists solely for compatibility with these binary types. As such, it is simply defined as an ordered sequence of zero or more byte values.

Additionally, as an implementation detail, the subtype of the binary data is carried around as a std::uint8_t, which is compatible with both of the binary data formats that use binary subtyping, (though the specific numbering is incompatible with each other, and it is up to the user to translate between them).

CBOR's RFC 7049 describes this type as:

Major type 2: a byte string. The string's length in bytes is represented following the rules for positive integers (major type 0).

MessagePack's documentation on the bin type family describes this type as:

Bin format family stores an byte array in 2, 3, or 5 bytes of extra bytes in addition to the size of the byte array.

BSON's specifications describe several binary types; however, this type is intended to represent the generic binary type which has the description:

Generic binary subtype - This is the most commonly used binary subtype and should be the 'default' for drivers and tools.

None of these impose any limitations on the internal representation other than the basic unit of storage be some type of array whose parts are decomposable into bytes.

The default representation of this binary format is a std::vector<std::uint8_t>, which is a very common way to represent a byte array in modern C++.

Default type

The default values for BinaryType is std::vector<std::uint8_t>

Storage

Binary Arrays are stored as pointers in a basic_json type. That is, for any access to array values, a pointer of the type binary_t* must be dereferenced.

Notes on subtypes

CBOR
- Binary values are represented as byte strings. No subtypes are supported and will be ignored when CBOR is written.
MessagePack
- If a subtype is given and the binary array contains exactly 1, 2, 4, 8, or 16 elements, the fixext family (fixext1, fixext2, fixext4, fixext8) is used. For other sizes, the ext family (ext8, ext16, ext32) is used. The subtype is then added as singed 8-bit integer.
- If no subtype is given, the bin family (bin8, bin16, bin32) is used.
BSON
- If a subtype is given, it is used and added as unsigned 8-bit integer.
- If no subtype is given, the generic binary subtype 0x00 is used.

See also: binary – create a binary array

Since: version 3.8.0

Definition at line 17479 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename CharType >

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::binary_writer = ::nlohmann::detail::binary_writer<basic_json, CharType>

private

Definition at line 16789 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::boolean_t = BooleanType

a type for a boolean

RFC 7159 implicitly describes a boolean as a type which differentiates the two literals true and false.

To store objects in C++, a type is defined by the template parameter BooleanType which chooses the type to use.

Default type

With the default values for BooleanType (bool), the default value for boolean_t is:

bool

Storage

Boolean values are stored directly inside a basic_json type.

Since: version 1.0.0

Definition at line 17197 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::cbor_tag_handler_t = detail::cbor_tag_handler_t

how to treat CBOR tags

Definition at line 16803 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::const_iterator = iter_impl<const basic_json>

a const iterator for a basic_json container

Definition at line 16868 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::const_pointer = typename std::allocator_traits<allocator_type>::const_pointer

the type of an element const pointer

Definition at line 16863 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::const_reference = const value_type&

the type of an element const reference

Definition at line 16850 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::const_reverse_iterator = json_reverse_iterator<typename basic_json::const_iterator>

a const reverse iterator for a basic_json container

Definition at line 16872 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::difference_type = std::ptrdiff_t

a type to represent differences between iterators

Definition at line 16853 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::error_handler_t = detail::error_handler_t

how to treat decoding errors

Definition at line 16801 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::exception = detail::exception

general exception of the basic_json class

This class is an extension of std::exception objects with a member id for exception ids. It is used as the base class for all exceptions thrown by the basic_json class. This class can hence be used as "wildcard" to catch exceptions.

Subclasses:

parse_error for exceptions indicating a parse error
invalid_iterator for exceptions indicating errors with iterators
type_error for exceptions indicating executing a member function with a wrong type
out_of_range for exceptions indicating access out of the defined range
other_error for exceptions indicating other library errors

{The following code shows how arbitrary library exceptions can be caught.,exception}

Since: version 3.0.0

Definition at line 16820 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::initializer_list_t = std::initializer_list<detail::json_ref<basic_json>>

helper type for initializer lists of basic_json values

Definition at line 16805 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::input_format_t = detail::input_format_t

Definition at line 16807 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename BasicJsonType >

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::internal_iterator = ::nlohmann::detail::internal_iterator<BasicJsonType>

private

Definition at line 16777 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::invalid_iterator = detail::invalid_iterator

exception indicating errors with iterators

This exception is thrown if iterators passed to a library function do not match the expected semantics.

Exceptions have ids 2xx.

name / id	example message	description
json.exception.invalid_iterator.201	iterators are not compatible	The iterators passed to constructor basic_json(InputIT first, InputIT last) are not compatible, meaning they do not belong to the same container. Therefore, the range (first, last) is invalid.
json.exception.invalid_iterator.202	iterator does not fit current value	In an erase or insert function, the passed iterator pos does not belong to the JSON value for which the function was called. It hence does not define a valid position for the deletion/insertion.
json.exception.invalid_iterator.203	iterators do not fit current value	Either iterator passed to function erase(IteratorType first, IteratorType last) does not belong to the JSON value from which values shall be erased. It hence does not define a valid range to delete values from.
json.exception.invalid_iterator.204	iterators out of range	When an iterator range for a primitive type (number, boolean, or string) is passed to a constructor or an erase function, this range has to be exactly (begin(), end()), because this is the only way the single stored value is expressed. All other ranges are invalid.
json.exception.invalid_iterator.205	iterator out of range	When an iterator for a primitive type (number, boolean, or string) is passed to an erase function, the iterator has to be the begin() iterator, because it is the only way to address the stored value. All other iterators are invalid.
json.exception.invalid_iterator.206	cannot construct with iterators from null	The iterators passed to constructor basic_json(InputIT first, InputIT last) belong to a JSON null value and hence to not define a valid range.
json.exception.invalid_iterator.207	cannot use key() for non-object iterators	The key() member function can only be used on iterators belonging to a JSON object, because other types do not have a concept of a key.
json.exception.invalid_iterator.208	cannot use operator[] for object iterators	The operator[] to specify a concrete offset cannot be used on iterators belonging to a JSON object, because JSON objects are unordered.
json.exception.invalid_iterator.209	cannot use offsets with object iterators	The offset operators (+, -, +=, -=) cannot be used on iterators belonging to a JSON object, because JSON objects are unordered.
json.exception.invalid_iterator.210	iterators do not fit	The iterator range passed to the insert function are not compatible, meaning they do not belong to the same container. Therefore, the range (first, last) is invalid.
json.exception.invalid_iterator.211	passed iterators may not belong to container	The iterator range passed to the insert function must not be a subrange of the container to insert to.
json.exception.invalid_iterator.212	cannot compare iterators of different containers	When two iterators are compared, they must belong to the same container.
json.exception.invalid_iterator.213	cannot compare order of object iterators	The order of object iterators cannot be compared, because JSON objects are unordered.
json.exception.invalid_iterator.214	cannot get value	Cannot get value for iterator: Either the iterator belongs to a null value or it is an iterator to a primitive type (number, boolean, or string), but the iterator is different to begin().

{The following code shows how an invalid_iterator exception can be caught.,invalid_iterator}

See also: - exception for the base class of the library exceptions; - parse_error for exceptions indicating a parse error; - type_error for exceptions indicating executing a member function with a wrong type; - out_of_range for exceptions indicating access out of the defined range; - other_error for exceptions indicating other library errors

Since: version 3.0.0

Definition at line 16824 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename BasicJsonType >

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::iter_impl = ::nlohmann::detail::iter_impl<BasicJsonType>

private

Definition at line 16779 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename Iterator >

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::iteration_proxy = ::nlohmann::detail::iteration_proxy<Iterator>

private

Definition at line 16781 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::iterator = iter_impl<basic_json>

an iterator for a basic_json container

Definition at line 16866 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::json_pointer = ::nlohmann::json_pointer<basic_json>

JSON Pointer, see nlohmann::json_pointer.

Definition at line 16797 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename Base >

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::json_reverse_iterator = ::nlohmann::detail::json_reverse_iterator<Base>

private

Definition at line 16782 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::json_sax_t = json_sax<basic_json>

SAX interface type, see nlohmann::json_sax.

Definition at line 16809 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename T , typename SFINAE >

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::json_serializer = JSONSerializer<T, SFINAE>

Definition at line 16799 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::number_float_t = NumberFloatType

a type for a number (floating-point)

RFC 7159 describes numbers as follows:

The representation of numbers is similar to that used in most programming languages. A number is represented in base 10 using decimal digits. It contains an integer component that may be prefixed with an optional minus sign, which may be followed by a fraction part and/or an exponent part. Leading zeros are not allowed. (...) Numeric values that cannot be represented in the grammar below (such as Infinity and NaN) are not permitted.

This description includes both integer and floating-point numbers. However, C++ allows more precise storage if it is known whether the number is a signed integer, an unsigned integer or a floating-point number. Therefore, three different types, number_integer_t, number_unsigned_t and number_float_t are used.

To store floating-point numbers in C++, a type is defined by the template parameter NumberFloatType which chooses the type to use.

Default type

With the default values for NumberFloatType (double), the default value for number_float_t is:

double

Default behavior

The restrictions about leading zeros is not enforced in C++. Instead, leading zeros in floating-point literals will be ignored. Internally, the value will be stored as decimal number. For instance, the C++ floating-point literal 01.2 will be serialized to 1.2. During deserialization, leading zeros yield an error.
Not-a-number (NaN) values will be serialized to null.

Limits

RFC 7159 states:

This specification allows implementations to set limits on the range and precision of numbers accepted. Since software that implements IEEE 754-2008 binary64 (double precision) numbers is generally available and widely used, good interoperability can be achieved by implementations that expect no more precision or range than these provide, in the sense that implementations will approximate JSON numbers within the expected precision.

This implementation does exactly follow this approach, as it uses double precision floating-point numbers. Note values smaller than -1.79769313486232e+308 and values greater than 1.79769313486232e+308 will be stored as NaN internally and be serialized to null.

Storage

Floating-point number values are stored directly inside a basic_json type.

See also: number_integer_t – type for number values (integer); number_unsigned_t – type for number values (unsigned integer)

Since: version 1.0.0

Definition at line 17408 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::number_integer_t = NumberIntegerType

a type for a number (integer)

RFC 7159 describes numbers as follows:

The representation of numbers is similar to that used in most programming languages. A number is represented in base 10 using decimal digits. It contains an integer component that may be prefixed with an optional minus sign, which may be followed by a fraction part and/or an exponent part. Leading zeros are not allowed. (...) Numeric values that cannot be represented in the grammar below (such as Infinity and NaN) are not permitted.

This description includes both integer and floating-point numbers. However, C++ allows more precise storage if it is known whether the number is a signed integer, an unsigned integer or a floating-point number. Therefore, three different types, number_integer_t, number_unsigned_t and number_float_t are used.

To store integer numbers in C++, a type is defined by the template parameter NumberIntegerType which chooses the type to use.

Default type

With the default values for NumberIntegerType (int64_t), the default value for number_integer_t is:

int64_t

Default behavior

The restrictions about leading zeros is not enforced in C++. Instead, leading zeros in integer literals lead to an interpretation as octal number. Internally, the value will be stored as decimal number. For instance, the C++ integer literal 010 will be serialized to 8. During deserialization, leading zeros yield an error.
Not-a-number (NaN) values will be serialized to null.

Limits

RFC 7159 specifies:

An implementation may set limits on the range and precision of numbers.

When the default type is used, the maximal integer number that can be stored is 9223372036854775807 (INT64_MAX) and the minimal integer number that can be stored is -9223372036854775808 (INT64_MIN). Integer numbers that are out of range will yield over/underflow when used in a constructor. During deserialization, too large or small integer numbers will be automatically be stored as number_unsigned_t or number_float_t.

RFC 7159 further states:

Note that when such software is used, numbers that are integers and are in the range $[-2^{53}+1, 2^{53}-1]$ are interoperable in the sense that implementations will agree exactly on their numeric values.

As this range is a subrange of the exactly supported range [INT64_MIN, INT64_MAX], this class's integer type is interoperable.

Storage

Integer number values are stored directly inside a basic_json type.

See also: number_float_t – type for number values (floating-point); number_unsigned_t – type for number values (unsigned integer)

Since: version 1.0.0

Definition at line 17269 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::number_unsigned_t = NumberUnsignedType

a type for a number (unsigned)

RFC 7159 describes numbers as follows:

The representation of numbers is similar to that used in most programming languages. A number is represented in base 10 using decimal digits. It contains an integer component that may be prefixed with an optional minus sign, which may be followed by a fraction part and/or an exponent part. Leading zeros are not allowed. (...) Numeric values that cannot be represented in the grammar below (such as Infinity and NaN) are not permitted.

This description includes both integer and floating-point numbers. However, C++ allows more precise storage if it is known whether the number is a signed integer, an unsigned integer or a floating-point number. Therefore, three different types, number_integer_t, number_unsigned_t and number_float_t are used.

To store unsigned integer numbers in C++, a type is defined by the template parameter NumberUnsignedType which chooses the type to use.

Default type

With the default values for NumberUnsignedType (uint64_t), the default value for number_unsigned_t is:

uint64_t

Default behavior

The restrictions about leading zeros is not enforced in C++. Instead, leading zeros in integer literals lead to an interpretation as octal number. Internally, the value will be stored as decimal number. For instance, the C++ integer literal 010 will be serialized to 8. During deserialization, leading zeros yield an error.
Not-a-number (NaN) values will be serialized to null.

Limits

RFC 7159 specifies:

An implementation may set limits on the range and precision of numbers.

When the default type is used, the maximal integer number that can be stored is 18446744073709551615 (UINT64_MAX) and the minimal integer number that can be stored is 0. Integer numbers that are out of range will yield over/underflow when used in a constructor. During deserialization, too large or small integer numbers will be automatically be stored as number_integer_t or number_float_t.

RFC 7159 further states:

Note that when such software is used, numbers that are integers and are in the range $[-2^{53}+1, 2^{53}-1]$ are interoperable in the sense that implementations will agree exactly on their numeric values.

As this range is a subrange (when considered in conjunction with the number_integer_t type) of the exactly supported range [0, UINT64_MAX], this class's integer type is interoperable.

Storage

Integer number values are stored directly inside a basic_json type.

See also: number_float_t – type for number values (floating-point); number_integer_t – type for number values (integer)

Since: version 2.0.0

Definition at line 17340 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::object_comparator_t = std::less<StringType>

Definition at line 16982 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::object_t = ObjectType<StringType, basic_json, object_comparator_t, AllocatorType<std::pair<const StringType, basic_json>>>

a type for an object

RFC 7159 describes JSON objects as follows:

An object is an unordered collection of zero or more name/value pairs, where a name is a string and a value is a string, number, boolean, null, object, or array.

To store objects in C++, a type is defined by the template parameters described below.

Template Parameters

ObjectType	the container to store objects (e.g., `std::map` or `std::unordered_map`)
StringType	the type of the keys or names (e.g., `std::string`). The comparison function `std::less<StringType>` is used to order elements inside the container.
AllocatorType	the allocator to use for objects (e.g., `std::allocator`)

Default type

With the default values for ObjectType (std::map), StringType (std::string), and AllocatorType (std::allocator), the default value for object_t is:

std::map<
  std::string, // key_type
  basic_json, // value_type
  std::less<std::string>, // key_compare
  std::allocator<std::pair<const std::string, basic_json>> // allocator_type
>

Behavior

The choice of object_t influences the behavior of the JSON class. With the default type, objects have the following behavior:

When all names are unique, objects will be interoperable in the sense that all software implementations receiving that object will agree on the name-value mappings.
When the names within an object are not unique, it is unspecified which one of the values for a given key will be chosen. For instance, {"key": 2, "key": 1} could be equal to either {"key": 1} or {"key": 2}.
Internally, name/value pairs are stored in lexicographical order of the names. Objects will also be serialized (see dump) in this order. For instance, {"b": 1, "a": 2} and {"a": 2, "b": 1} will be stored and serialized as {"a": 2, "b": 1}.
When comparing objects, the order of the name/value pairs is irrelevant. This makes objects interoperable in the sense that they will not be affected by these differences. For instance, {"b": 1, "a": 2} and {"a": 2, "b": 1} will be treated as equal.

Limits

RFC 7159 specifies:

An implementation may set limits on the maximum depth of nesting.

In this class, the object's limit of nesting is not explicitly constrained. However, a maximum depth of nesting may be introduced by the compiler or runtime environment. A theoretical limit can be queried by calling the max_size function of a JSON object.

Storage

Objects are stored as pointers in a basic_json type. That is, for any access to object values, a pointer of type object_t* must be dereferenced.

See also: array_t – type for an array value

Since: version 1.0.0

Note: The order name/value pairs are added to the object is not preserved by the library. Therefore, iterating an object may return name/value pairs in a different order than they were originally stored. In fact, keys will be traversed in alphabetical order as std::map with std::less is used by default. Please note this behavior conforms to RFC 7159, because any order implements the specified "unordered" nature of JSON objects.

Definition at line 17072 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::other_error = detail::other_error

exception indicating other library errors

This exception is thrown in case of errors that cannot be classified with the other exception types.

Exceptions have ids 5xx.

name / id	example message	description
json.exception.other_error.501	unsuccessful: {"op":"test","path":"/baz", "value":"bar"}	A JSON Patch operation 'test' failed. The unsuccessful operation is also printed.

See also: - exception for the base class of the library exceptions; - parse_error for exceptions indicating a parse error; - invalid_iterator for exceptions indicating errors with iterators; - type_error for exceptions indicating executing a member function with a wrong type; - out_of_range for exceptions indicating access out of the defined range

{The following code shows how an other_error exception can be caught.,other_error}

Since: version 3.0.0

Definition at line 16830 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::out_of_range = detail::out_of_range

exception indicating access out of the defined range

This exception is thrown in case a library function is called on an input parameter that exceeds the expected range, for instance in case of array indices or nonexisting object keys.

Exceptions have ids 4xx.

name / id	example message	description
json.exception.out_of_range.401	array index 3 is out of range	The provided array index i is larger than size-1.
json.exception.out_of_range.402	array index '-' (3) is out of range	The special array index `-` in a JSON Pointer never describes a valid element of the array, but the index past the end. That is, it can only be used to add elements at this position, but not to read it.
json.exception.out_of_range.403	key 'foo' not found	The provided key was not found in the JSON object.
json.exception.out_of_range.404	unresolved reference token 'foo'	A reference token in a JSON Pointer could not be resolved.
json.exception.out_of_range.405	JSON pointer has no parent	The JSON Patch operations 'remove' and 'add' can not be applied to the root element of the JSON value.
json.exception.out_of_range.406	number overflow parsing '10E1000'	A parsed number could not be stored as without changing it to NaN or INF.
json.exception.out_of_range.407	number overflow serializing '9223372036854775808'	UBJSON and BSON only support integer numbers up to 9223372036854775807. (until version 3.8.0)
json.exception.out_of_range.408	excessive array size: 8658170730974374167	The size (following `#`) of an UBJSON array or object exceeds the maximal capacity.
json.exception.out_of_range.409	BSON key cannot contain code point U+0000 (at byte 2)	Key identifiers to be serialized to BSON cannot contain code point U+0000, since the key is stored as zero-terminated c-string

{The following code shows how an out_of_range exception can be caught.,out_of_range}

See also: - exception for the base class of the library exceptions; - parse_error for exceptions indicating a parse error; - invalid_iterator for exceptions indicating errors with iterators; - type_error for exceptions indicating executing a member function with a wrong type; - other_error for exceptions indicating other library errors

Since: version 3.0.0

Definition at line 16828 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename CharType >

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::output_adapter_t = ::nlohmann::detail::output_adapter_t<CharType>

private

Definition at line 16785 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::parse_error = detail::parse_error

exception indicating a parse error

This exception is thrown by the library when a parse error occurs. Parse errors can occur during the deserialization of JSON text, CBOR, MessagePack, as well as when using JSON Patch.

Member byte holds the byte index of the last read character in the input file.

Exceptions have ids 1xx.

name / id	example message	description
json.exception.parse_error.101	parse error at 2: unexpected end of input; expected string literal	This error indicates a syntax error while deserializing a JSON text. The error message describes that an unexpected token (character) was encountered, and the member byte indicates the error position.
json.exception.parse_error.102	parse error at 14: missing or wrong low surrogate	JSON uses the `\uxxxx` format to describe Unicode characters. Code points above above 0xFFFF are split into two `\uxxxx` entries ("surrogate pairs"). This error indicates that the surrogate pair is incomplete or contains an invalid code point.
json.exception.parse_error.103	parse error: code points above 0x10FFFF are invalid	Unicode supports code points up to 0x10FFFF. Code points above 0x10FFFF are invalid.
json.exception.parse_error.104	parse error: JSON patch must be an array of objects	RFC 6902 requires a JSON Patch document to be a JSON document that represents an array of objects.
json.exception.parse_error.105	parse error: operation must have string member 'op'	An operation of a JSON Patch document must contain exactly one "op" member, whose value indicates the operation to perform. Its value must be one of "add", "remove", "replace", "move", "copy", or "test"; other values are errors.
json.exception.parse_error.106	parse error: array index '01' must not begin with '0'	An array index in a JSON Pointer (RFC 6901) may be `0` or any number without a leading `0`.
json.exception.parse_error.107	parse error: JSON pointer must be empty or begin with '/' - was: 'foo'	A JSON Pointer must be a Unicode string containing a sequence of zero or more reference tokens, each prefixed by a `/` character.
json.exception.parse_error.108	parse error: escape character '~' must be followed with '0' or '1'	In a JSON Pointer, only `~0` and `~1` are valid escape sequences.
json.exception.parse_error.109	parse error: array index 'one' is not a number	A JSON Pointer array index must be a number.
json.exception.parse_error.110	parse error at 1: cannot read 2 bytes from vector	When parsing CBOR or MessagePack, the byte vector ends before the complete value has been read.
json.exception.parse_error.112	parse error at 1: error reading CBOR; last byte: 0xF8	Not all types of CBOR or MessagePack are supported. This exception occurs if an unsupported byte was read.
json.exception.parse_error.113	parse error at 2: expected a CBOR string; last byte: 0x98	While parsing a map key, a value that is not a string has been read.
json.exception.parse_error.114	parse error: Unsupported BSON record type 0x0F	The parsing of the corresponding BSON record type is not implemented (yet).
json.exception.parse_error.115	parse error at byte 5: syntax error while parsing UBJSON high-precision number: invalid number text: 1A	A UBJSON high-precision number could not be parsed.

Note: For an input with n bytes, 1 is the index of the first character and n+1 is the index of the terminating null byte or the end of file. This also holds true when reading a byte vector (CBOR or MessagePack).

{The following code shows how a parse_error exception can be caught.,parse_error}

See also: - exception for the base class of the library exceptions; - invalid_iterator for exceptions indicating errors with iterators; - type_error for exceptions indicating executing a member function with a wrong type; - out_of_range for exceptions indicating access out of the defined range; - other_error for exceptions indicating other library errors

Since: version 3.0.0

Definition at line 16822 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::parse_event_t = detail::parse_event_t

parser event types

The parser callback distinguishes the following events:

object_start: the parser read { and started to process a JSON object
key: the parser read a key of a value in an object
object_end: the parser read } and finished processing a JSON object
array_start: the parser read [ and started to process a JSON array
array_end: the parser read ] and finished processing a JSON array
value: the parser finished reading a JSON value

Example when certain parse events are triggered

See also: parser_callback_t for more information and examples

Definition at line 17821 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::parser_callback_t = detail::parser_callback_t<basic_json>

per-element parser callback type

With a parser callback function, the result of parsing a JSON text can be influenced. When passed to parse, it is called on certain events (passed as parse_event_t via parameter event) with a set recursion depth depth and context JSON value parsed. The return value of the callback function is a boolean indicating whether the element that emitted the callback shall be kept or not.

We distinguish six scenarios (determined by the event type) in which the callback function can be called. The following table describes the values of the parameters depth, event, and parsed.

parameter event	description	parameter depth	parameter parsed
parse_event_t::object_start	the parser read `{` and started to process a JSON object	depth of the parent of the JSON object	a JSON value with type discarded
parse_event_t::key	the parser read a key of a value in an object	depth of the currently parsed JSON object	a JSON string containing the key
parse_event_t::object_end	the parser read `}` and finished processing a JSON object	depth of the parent of the JSON object	the parsed JSON object
parse_event_t::array_start	the parser read `[` and started to process a JSON array	depth of the parent of the JSON array	a JSON value with type discarded
parse_event_t::array_end	the parser read `]` and finished processing a JSON array	depth of the parent of the JSON array	the parsed JSON array
parse_event_t::value	the parser finished reading a JSON value	depth of the value	the parsed JSON value

Example when certain parse events are triggered

Discarding a value (i.e., returning false) has different effects depending on the context in which function was called:

Discarded values in structured types are skipped. That is, the parser will behave as if the discarded value was never read.
In case a value outside a structured type is skipped, it is replaced with null. This case happens if the top-level element is skipped.

Parameters

[in]	depth	the depth of the recursion during parsing
[in]	event	an event of type parse_event_t indicating the context in the callback function has been called
[in,out]	parsed	the current intermediate parse result; note that writing to this value has no effect for parse_event_t::key events

Returns: Whether the JSON value which called the function during parsing should be kept (true) or not (false). In the latter case, it is either skipped completely or replaced by an empty discarded object.

See also: parse for examples

Since: version 1.0.0

Definition at line 17872 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::pointer = typename std::allocator_traits<allocator_type>::pointer

the type of an element pointer

Definition at line 16861 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::primitive_iterator_t = ::nlohmann::detail::primitive_iterator_t

private

Definition at line 16775 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::reference = value_type&

the type of an element reference

Definition at line 16848 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::reverse_iterator = json_reverse_iterator<typename basic_json::iterator>

a reverse iterator for a basic_json container

Definition at line 16870 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::size_type = std::size_t

a type to represent container sizes

Definition at line 16855 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::string_t = StringType

a type for a string

RFC 7159 describes JSON strings as follows:

A string is a sequence of zero or more Unicode characters.

To store objects in C++, a type is defined by the template parameter described below. Unicode values are split by the JSON class into byte-sized characters during deserialization.

Template Parameters

StringType the container to store strings (e.g., std::string). Note this container is used for keys/names in objects, see object_t.

Default type

With the default values for StringType (std::string), the default value for string_t is:

std::string

Encoding

Strings are stored in UTF-8 encoding. Therefore, functions like std::string::size() or std::string::length() return the number of bytes in the string rather than the number of characters or glyphs.

String comparison

RFC 7159 states:

Software implementations are typically required to test names of object members for equality. Implementations that transform the textual representation into sequences of Unicode code units and then perform the comparison numerically, code unit by code unit, are interoperable in the sense that implementations will agree in all cases on equality or inequality of two strings. For example, implementations that compare strings with escaped characters unconverted may incorrectly find that "a\\\\b" and "a\\u005Cb" are not equal.

This implementation is interoperable as it does compare strings code unit by code unit.

Storage

String values are stored as pointers in a basic_json type. That is, for any access to string values, a pointer of type string_t* must be dereferenced.

Since: version 1.0.0

Definition at line 17171 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::type_error = detail::type_error

exception indicating executing a member function with a wrong type

This exception is thrown in case of a type error; that is, a library function is executed on a JSON value whose type does not match the expected semantics.

Exceptions have ids 3xx.

name / id	example message	description
json.exception.type_error.301	cannot create object from initializer list	To create an object from an initializer list, the initializer list must consist only of a list of pairs whose first element is a string. When this constraint is violated, an array is created instead.
json.exception.type_error.302	type must be object, but is array	During implicit or explicit value conversion, the JSON type must be compatible to the target type. For instance, a JSON string can only be converted into string types, but not into numbers or boolean types.
json.exception.type_error.303	incompatible ReferenceType for get_ref, actual type is object	To retrieve a reference to a value stored in a basic_json object with get_ref, the type of the reference must match the value type. For instance, for a JSON array, the ReferenceType must be array_t &.
json.exception.type_error.304	cannot use at() with string	The at() member functions can only be executed for certain JSON types.
json.exception.type_error.305	cannot use operator[] with string	The operator[] member functions can only be executed for certain JSON types.
json.exception.type_error.306	cannot use value() with string	The value() member functions can only be executed for certain JSON types.
json.exception.type_error.307	cannot use erase() with string	The erase() member functions can only be executed for certain JSON types.
json.exception.type_error.308	cannot use push_back() with string	The push_back() and operator+= member functions can only be executed for certain JSON types.
json.exception.type_error.309	cannot use insert() with	The insert() member functions can only be executed for certain JSON types.
json.exception.type_error.310	cannot use swap() with number	The swap() member functions can only be executed for certain JSON types.
json.exception.type_error.311	cannot use emplace_back() with string	The emplace_back() member function can only be executed for certain JSON types.
json.exception.type_error.312	cannot use update() with string	The update() member functions can only be executed for certain JSON types.
json.exception.type_error.313	invalid value to unflatten	The unflatten function converts an object whose keys are JSON Pointers back into an arbitrary nested JSON value. The JSON Pointers must not overlap, because then the resulting value would not be well defined.
json.exception.type_error.314	only objects can be unflattened	The unflatten function only works for an object whose keys are JSON Pointers.
json.exception.type_error.315	values in object must be primitive	The unflatten function only works for an object whose keys are JSON Pointers and whose values are primitive.
json.exception.type_error.316	invalid UTF-8 byte at index 10: 0x7E	The dump function only works with UTF-8 encoded strings; that is, if you assign a `std::string` to a JSON value, make sure it is UTF-8 encoded.
json.exception.type_error.317	JSON value cannot be serialized to requested format	The dynamic type of the object cannot be represented in the requested serialization format (e.g. a raw `true` or `null` JSON object cannot be serialized to BSON)

{The following code shows how a type_error exception can be caught.,type_error}

See also: - exception for the base class of the library exceptions; - parse_error for exceptions indicating a parse error; - invalid_iterator for exceptions indicating errors with iterators; - out_of_range for exceptions indicating access out of the defined range; - other_error for exceptions indicating other library errors

Since: version 3.0.0

Definition at line 16826 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::value_t = detail::value_t

Definition at line 16795 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::value_type = basic_json

the type of elements in a basic_json container

Definition at line 16845 of file json.hpp.

Constructor & Destructor Documentation

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::basic_json ( const value_t v )

inline

create an empty value with a given type

Create an empty JSON value with a given type. The value will be default initialized with an empty value which depends on the type:

Value type	initial value
null	`null`
boolean	`false`
string	`""`
number	`0`
object	`{}`
array	`[]`
binary	empty array

Parameters

[in] v the type of the value to create

Constant.

Strong guarantee: if an exception is thrown, there are no changes to any JSON value.

{The following code shows the constructor for different value_t values,basic_json__value_t}

See also: clear() – restores the postcondition of this constructor

Since: version 1.0.0

Definition at line 17913 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::basic_json ( std::nullptr_t = nullptr )

inlinenoexcept

create a null object

Create a null JSON value. It either takes a null pointer as parameter (explicitly creating null) or no parameter (implicitly creating null). The passed null pointer itself is not read – it is only used to choose the right constructor.

Constant.

No-throw guarantee: this constructor never throws exceptions.

{The following code shows the constructor with and without a null pointer parameter.,basic_json__nullptr_t}

Since: version 1.0.0

Definition at line 17937 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename CompatibleType , typename U = detail::uncvref_t<CompatibleType>, detail::enable_if_t< !detail::is_basic_json< U >::value &&detail::is_compatible_type< basic_json_t, U >::value, int > = 0>

nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::basic_json ( CompatibleType && val )

inlinenoexcept

create a JSON value

This is a "catch all" constructor for all compatible JSON types; that is, types for which a to_json() method exists. The constructor forwards the parameter val to that method (to json_serializer<U>::to_json method with U = uncvref_t<CompatibleType>, to be exact).

Template type CompatibleType includes, but is not limited to, the following types:

arrays: array_t and all kinds of compatible containers such as std::vector, std::deque, std::list, std::forward_list, std::array, std::valarray, std::set, std::unordered_set, std::multiset, and std::unordered_multiset with a value_type from which a basic_json value can be constructed.
objects: object_t and all kinds of compatible associative containers such as std::map, std::unordered_map, std::multimap, and std::unordered_multimap with a key_type compatible to string_t and a value_type from which a basic_json value can be constructed.
strings: string_t, string literals, and all compatible string containers can be used.
numbers: number_integer_t, number_unsigned_t, number_float_t, and all convertible number types such as int, size_t, int64_t, float or double can be used.
boolean: boolean_t / bool can be used.
binary: binary_t / std::vector<uint8_t> may be used, unfortunately because string literals cannot be distinguished from binary character arrays by the C++ type system, all types compatible with const char* will be directed to the string constructor instead. This is both for backwards compatibility, and due to the fact that a binary type is not a standard JSON type.

See the examples below.

Template Parameters

CompatibleType

a type such that:

CompatibleType is not derived from std::istream,
CompatibleType is not basic_json (to avoid hijacking copy/move constructors),
CompatibleType is not a different basic_json type (i.e. with different template arguments)
CompatibleType is not a basic_json nested type (e.g., json_pointer, iterator, etc ...)
json_serializer<U> has a to_json(basic_json_t&, CompatibleType&&) method

U = uncvref_t<CompatibleType>

Parameters

[in] val the value to be forwarded to the respective constructor

Usually linear in the size of the passed val, also depending on the implementation of the called to_json() method.

Depends on the called constructor. For types directly supported by the library (i.e., all types for which no to_json() function was provided), strong guarantee holds: if an exception is thrown, there are no changes to any JSON value.

{The following code shows the constructor with several compatible types.,basic_json__CompatibleType}

Since: version 2.1.0

Definition at line 18010 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename BasicJsonType , detail::enable_if_t< detail::is_basic_json< BasicJsonType >::value &&!std::is_same< basic_json, BasicJsonType >::value, int > = 0>

nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::basic_json ( const BasicJsonType & val )

inline

create a JSON value from an existing one

This is a constructor for existing basic_json types. It does not hijack copy/move constructors, since the parameter has different template arguments than the current ones.

The constructor tries to convert the internal m_value of the parameter.

Template Parameters

BasicJsonType

a type such that:

BasicJsonType is a basic_json type.
BasicJsonType has different template arguments than basic_json_t.

Parameters

[in] val the basic_json value to be converted.

Usually linear in the size of the passed val, also depending on the implementation of the called to_json() method.

Depends on the called constructor. For types directly supported by the library (i.e., all types for which no to_json() function was provided), strong guarantee holds: if an exception is thrown, there are no changes to any JSON value.

Since: version 3.2.0

Definition at line 18047 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::basic_json	(	initializer_list_t	init,
		bool	type_deduction = `true`,
		value_t	manual_type = `value_t::array`
	)

inline

create a container (array or object) from an initializer list

Creates a JSON value of type array or object from the passed initializer list init. In case type_deduction is true (default), the type of the JSON value to be created is deducted from the initializer list init according to the following rules:

If the list is empty, an empty JSON object value {} is created.
If the list consists of pairs whose first element is a string, a JSON object value is created where the first elements of the pairs are treated as keys and the second elements are as values.
In all other cases, an array is created.

The rules aim to create the best fit between a C++ initializer list and JSON values. The rationale is as follows:

The empty initializer list is written as {} which is exactly an empty JSON object.
C++ has no way of describing mapped types other than to list a list of pairs. As JSON requires that keys must be of type string, rule 2 is the weakest constraint one can pose on initializer lists to interpret them as an object.
In all other cases, the initializer list could not be interpreted as JSON object type, so interpreting it as JSON array type is safe.

With the rules described above, the following JSON values cannot be expressed by an initializer list:

the empty array ([]): use array(initializer_list_t) with an empty initializer list in this case
arrays whose elements satisfy rule 2: use array(initializer_list_t) with the same initializer list in this case

Note: When used without parentheses around an empty initializer list, basic_json() is called instead of this function, yielding the JSON null value.

Parameters

[in]	init	initializer list with JSON values
[in]	type_deduction	internal parameter; when set to `true`, the type of the JSON value is deducted from the initializer list init; when set to `false`, the type provided via manual_type is forced. This mode is used by the functions array(initializer_list_t) and object(initializer_list_t).
[in]	manual_type	internal parameter; when type_deduction is set to `false`, the created JSON value will use the provided type (only value_t::array and value_t::object are valid); when type_deduction is set to `true`, this parameter has no effect

Exceptions

type_error.301 if type_deduction is false, manual_type is value_t::object, but init contains an element which is not a pair whose first element is a string. In this case, the constructor could not create an object. If type_deduction would have be true, an array would have been created. See object(initializer_list_t) for an example.

Linear in the size of the initializer list init.

Strong guarantee: if an exception is thrown, there are no changes to any JSON value.

{The example below shows how JSON values are created from initializer lists.,basic_json__list_init_t}

See also: array(initializer_list_t) – create a JSON array value from an initializer list; object(initializer_list_t) – create a JSON object value from an initializer list

Since: version 1.0.0

Definition at line 18170 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::basic_json	(	size_type	cnt,
		const basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType > &	val
	)

inline

construct an array with count copies of given value

Constructs a JSON array value by creating cnt copies of a passed value. In case cnt is 0, an empty array is created.

Parameters

[in]	cnt	the number of JSON copies of val to create
[in]	val	the JSON value to copy

Postcondition: std::distance(begin(),end()) == cnt holds.

Linear in cnt.

Strong guarantee: if an exception is thrown, there are no changes to any JSON value.

{The following code shows examples for the basic_json(size_type\, const basic_json&) constructor.,basic_json__size_type_basic_json}

Since: version 1.0.0

Definition at line 18424 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<class InputIT , typename std::enable_if< std::is_same< InputIT, typename basic_json_t::iterator >::value||std::is_same< InputIT, typename basic_json_t::const_iterator >::value, int >::type = 0>

nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::basic_json	(	InputIT	first,
		InputIT	last
	)

inline

construct a JSON container given an iterator range

Constructs the JSON value with the contents of the range [first, last). The semantics depends on the different types a JSON value can have:

In case of a null type, invalid_iterator.206 is thrown.
In case of other primitive types (number, boolean, or string), first must be begin() and last must be end(). In this case, the value is copied. Otherwise, invalid_iterator.204 is thrown.
In case of structured types (array, object), the constructor behaves as similar versions for std::vector or std::map; that is, a JSON array or object is constructed from the values in the range.

Template Parameters

InputIT an input iterator type (iterator or const_iterator)

Parameters

[in]	first	begin of the range to copy from (included)
[in]	last	end of the range to copy from (excluded)

Precondition: Iterators first and last must be initialized. This precondition is enforced with an assertion (see warning). If assertions are switched off, a violation of this precondition yields undefined behavior.; Range [first, last) is valid. Usually, this precondition cannot be checked efficiently. Only certain edge cases are detected; see the description of the exceptions below. A violation of this precondition yields undefined behavior.

Warning: A precondition is enforced with a runtime assertion that will result in calling std::abort if this precondition is not met. Assertions can be disabled by defining NDEBUG at compile time. See https://en.cppreference.com/w/cpp/error/assert for more information.

Exceptions

invalid_iterator.201	if iterators first and last are not compatible (i.e., do not belong to the same JSON value). In this case, the range `[first, last)` is undefined.
invalid_iterator.204	if iterators first and last belong to a primitive type (number, boolean, or string), but first does not point to the first element any more. In this case, the range `[first, last)` is undefined. See example code below.
invalid_iterator.206	if iterators first and last belong to a null value. In this case, the range `[first, last)` is undefined.

Linear in distance between first and last.

Strong guarantee: if an exception is thrown, there are no changes to any JSON value.

{The example below shows several ways to create JSON values by specifying a subrange with iterators.,basic_json__InputIt_InputIt}

Since: version 1.0.0

Definition at line 18489 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename JsonRef , detail::enable_if_t< detail::conjunction< detail::is_json_ref< JsonRef >, std::is_same< typename JsonRef::value_type, basic_json >>::value, int > = 0>

nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::basic_json ( const JsonRef & ref )

inline

Definition at line 18592 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::basic_json ( const basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType > & other )

inline

copy constructor

Creates a copy of a given JSON value.

Parameters

[in] other the JSON value to copy

Postcondition: *this == other

Linear in the size of other.

Strong guarantee: if an exception is thrown, there are no changes to any JSON value.

This function helps basic_json satisfying the Container requirements:

The complexity is linear.
As postcondition, it holds: other == basic_json(other).

{The following code shows an example for the copy constructor.,basic_json__basic_json}

Since: version 1.0.0

Definition at line 18619 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::basic_json ( basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType > && other )

inlinenoexcept

move constructor

Move constructor. Constructs a JSON value with the contents of the given value other using move semantics. It "steals" the resources from other and leaves it as JSON null value.

Parameters

[in,out] other value to move to this object

Postcondition: *this has the same value as other before the call.; other is a JSON null value.

Constant.

No-throw guarantee: this constructor never throws exceptions.

This function helps basic_json satisfying the MoveConstructible requirements.

{The code below shows the move constructor explicitly called via std::move.,basic_json__moveconstructor}

Since: version 1.0.0

Definition at line 18708 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::~basic_json ( )

inlinenoexcept

destructor

Destroys the JSON value and frees all allocated memory.

Linear.

This function helps basic_json satisfying the Container requirements:

The complexity is linear.
All stored elements are destroyed and all memory is freed.

Since: version 1.0.0

Definition at line 18778 of file json.hpp.

Member Function Documentation

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename InputType >

static bool nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::accept	(	InputType &&	i,
		const bool	ignore_comments = `false`
	)

inlinestatic

check if the input is valid JSON

Unlike the parse(InputType&&, const parser_callback_t,const bool) function, this function neither throws an exception in case of invalid JSON input (i.e., a parse error) nor creates diagnostic information.

Template Parameters

InputType

A compatible input, for instance

an std::istream object
a FILE pointer
a C-style array of characters
a pointer to a null-terminated string of single byte characters
an object obj for which begin(obj) and end(obj) produces a valid pair of iterators.

Parameters

[in]	i	input to read from
[in]	ignore_comments	whether comments should be ignored and treated like whitespace (true) or yield a parse error (true); (optional, false by default)

Returns: Whether the input read from i is valid JSON.

Linear in the length of the input. The parser is a predictive LL(1) parser.

Note: A UTF-8 byte order mark is silently ignored.

{The example below demonstrates the accept() function reading from a string.,accept__string}

Definition at line 23311 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename IteratorType >

static bool nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::accept	(	IteratorType	first,
		IteratorType	last,
		const bool	ignore_comments = `false`
	)

inlinestatic

Definition at line 23318 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

static JSON_HEDLEY_WARN_UNUSED_RESULT bool nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::accept	(	detail::span_input_adapter &&	i,
		const bool	ignore_comments = `false`
	)

inlinestatic

Definition at line 23326 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::array ( initializer_list_t init = {} )

inlinestatic

explicitly create an array from an initializer list

Creates a JSON array value from a given initializer list. That is, given a list of values a, b, c, creates the JSON value [a, b, c]. If the initializer list is empty, the empty array [] is created.

Note

This function is only needed to express two edge cases that cannot be realized with the initializer list constructor (basic_json(initializer_list_t, bool, value_t)). These cases are:

creating an array whose elements are all pairs whose first element is a string – in this case, the initializer list constructor would create an object, taking the first elements as keys
creating an empty array – passing the empty initializer list to the initializer list constructor yields an empty object

Parameters

[in] init initializer list with JSON values to create an array from (optional)

Returns: JSON array value

Linear in the size of init.

Strong guarantee: if an exception is thrown, there are no changes to any JSON value.

{The following code shows an example for the array function.,array}

See also: basic_json(initializer_list_t, bool, value_t) – create a JSON value from an initializer list; object(initializer_list_t) – create a JSON object value from an initializer list

Since: version 1.0.0

Definition at line 18353 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::assert_invariant ( ) const

inlineprivatenoexcept

checks the class invariants

This function asserts the class invariants. It needs to be called at the end of every constructor to make sure that created objects respect the invariant. Furthermore, it has to be called each time the type of a JSON value is changed, because the invariant expresses a relationship between m_type and m_value.

Definition at line 17793 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

reference nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::at ( size_type idx )

inline

access specified array element with bounds checking

Returns a reference to the element at specified location idx, with bounds checking.

Parameters

[in] idx index of the element to access

Returns: reference to the element at index idx

Exceptions

type_error.304	if the JSON value is not an array; in this case, calling `at` with an index makes no sense. See example below.
out_of_range.401	if the index idx is out of range of the array; that is, `idx >= size()`. See example below.

Strong guarantee: if an exception is thrown, there are no changes in the JSON value.

Constant.

Since: version 1.0.0

{The example below shows how array elements can be read and written using at(). It also demonstrates the different exceptions that can be thrown.,at__size_type}

Definition at line 19876 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

const_reference nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::at ( size_type idx ) const

inline

access specified array element with bounds checking

Returns a const reference to the element at specified location idx, with bounds checking.

Parameters

[in] idx index of the element to access

Returns: const reference to the element at index idx

Exceptions

type_error.304	if the JSON value is not an array; in this case, calling `at` with an index makes no sense. See example below.
out_of_range.401	if the index idx is out of range of the array; that is, `idx >= size()`. See example below.

Strong guarantee: if an exception is thrown, there are no changes in the JSON value.

Constant.

Since: version 1.0.0

{The example below shows how array elements can be read using at(). It also demonstrates the different exceptions that can be thrown., at__size_type_const}

Definition at line 19923 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

reference nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::at ( const typename object_t::key_type & key )

inline

access specified object element with bounds checking

Returns a reference to the element at with specified key key, with bounds checking.

Parameters

[in] key key of the element to access

Returns: reference to the element at key key

Exceptions

type_error.304	if the JSON value is not an object; in this case, calling `at` with a key makes no sense. See example below.
out_of_range.403	if the key key is is not stored in the object; that is, `find(key) == end()`. See example below.

Strong guarantee: if an exception is thrown, there are no changes in the JSON value.

Logarithmic in the size of the container.

See also: operator[](const typename object_t::key_type&) for unchecked access by reference; value() for access by value with a default value

Since: version 1.0.0

{The example below shows how object elements can be read and written using at(). It also demonstrates the different exceptions that can be thrown.,at__object_t_key_type}

Definition at line 19974 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

const_reference nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::at ( const typename object_t::key_type & key ) const

inline

access specified object element with bounds checking

Returns a const reference to the element at with specified key key, with bounds checking.

Parameters

[in] key key of the element to access

Returns: const reference to the element at key key

Exceptions

type_error.304	if the JSON value is not an object; in this case, calling `at` with a key makes no sense. See example below.
out_of_range.403	if the key key is is not stored in the object; that is, `find(key) == end()`. See example below.

Strong guarantee: if an exception is thrown, there are no changes in the JSON value.

Logarithmic in the size of the container.

See also: operator[](const typename object_t::key_type&) for unchecked access by reference; value() for access by value with a default value

Since: version 1.0.0

{The example below shows how object elements can be read using at(). It also demonstrates the different exceptions that can be thrown., at__object_t_key_type_const}

Definition at line 20025 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

reference nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::at ( const json_pointer & ptr )

inline

access specified element via JSON Pointer

Returns a reference to the element at with specified JSON pointer ptr, with bounds checking.

Parameters

[in] ptr JSON pointer to the desired element

Returns: reference to the element pointed to by ptr

Exceptions

parse_error.106	if an array index in the passed JSON pointer ptr begins with '0'. See example below.
parse_error.109	if an array index in the passed JSON pointer ptr is not a number. See example below.
out_of_range.401	if an array index in the passed JSON pointer ptr is out of range. See example below.
out_of_range.402	if the array index '-' is used in the passed JSON pointer ptr. As `at` provides checked access (and no elements are implicitly inserted), the index '-' is always invalid. See example below.
out_of_range.403	if the JSON pointer describes a key of an object which cannot be found. See example below.
out_of_range.404	if the JSON pointer ptr can not be resolved. See example below.

Strong guarantee: if an exception is thrown, there are no changes in the JSON value.

Constant.

Since: version 2.0.0

{The behavior is shown in the example.,at_json_pointer}

Definition at line 24577 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

const_reference nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::at ( const json_pointer & ptr ) const

inline

access specified element via JSON Pointer

Returns a const reference to the element at with specified JSON pointer ptr, with bounds checking.

Parameters

[in] ptr JSON pointer to the desired element

Returns: reference to the element pointed to by ptr

Exceptions

parse_error.106	if an array index in the passed JSON pointer ptr begins with '0'. See example below.
parse_error.109	if an array index in the passed JSON pointer ptr is not a number. See example below.
out_of_range.401	if an array index in the passed JSON pointer ptr is out of range. See example below.
out_of_range.402	if the array index '-' is used in the passed JSON pointer ptr. As `at` provides checked access (and no elements are implicitly inserted), the index '-' is always invalid. See example below.
out_of_range.403	if the JSON pointer describes a key of an object which cannot be found. See example below.
out_of_range.404	if the JSON pointer ptr can not be resolved. See example below.

Strong guarantee: if an exception is thrown, there are no changes in the JSON value.

Constant.

Since: version 2.0.0

{The behavior is shown in the example.,at_json_pointer_const}

Definition at line 24620 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

reference nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::back ( )

inline

access the last element

Returns a reference to the last element in the container. For a JSON container c, the expression c.back() is equivalent to

auto tmp = c.end();
--tmp;
return *tmp;

Returns: In case of a structured type (array or object), a reference to the last element is returned. In case of number, string, boolean, or binary values, a reference to the value is returned.

Constant.

Precondition: The JSON value must not be null (would throw std::out_of_range) or an empty array or object (undefined behavior, guarded by assertions).

Postcondition: The JSON value remains unchanged.

Exceptions

invalid_iterator.214 when called on a null value. See example below.

{The following code shows an example for back().,back}

See also: front() – access the first element

Since: version 1.0.0

Definition at line 20532 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

const_reference nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::back ( ) const

inline

access the last element

Returns a reference to the last element in the container. For a JSON container c, the expression c.back() is equivalent to

auto tmp = c.end();
--tmp;
return *tmp;

Returns: In case of a structured type (array or object), a reference to the last element is returned. In case of number, string, boolean, or binary values, a reference to the value is returned.

Constant.

Precondition: The JSON value must not be null (would throw std::out_of_range) or an empty array or object (undefined behavior, guarded by assertions).

Postcondition: The JSON value remains unchanged.

Exceptions

invalid_iterator.214 when called on a null value. See example below.

{The following code shows an example for back().,back}

See also: front() – access the first element

Since: version 1.0.0

Definition at line 20542 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

iterator nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::begin ( )

inlinenoexcept

returns an iterator to the first element

Returns an iterator to the first element.

Illustration from cppreference.com

Returns: iterator to the first element

Constant.

This function helps basic_json satisfying the Container requirements:

The complexity is constant.

{The following code shows an example for begin().,begin}

See also: cbegin() – returns a const iterator to the beginning; end() – returns an iterator to the end; cend() – returns a const iterator to the end

Since: version 1.0.0

Definition at line 21049 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

const_iterator nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::begin ( ) const

inlinenoexcept

returns a const iterator to the first element

Returns a const iterator to the first element.

Illustration from cppreference.com

Returns: const iterator to the first element

Constant.

This function helps basic_json satisfying the Container requirements:

The complexity is constant.
Has the semantics of const_cast<const basic_json&>(*this).begin().

{The following code shows an example for cbegin().,cbegin}

See also: begin() – returns an iterator to the beginning; end() – returns an iterator to the end; cend() – returns a const iterator to the end

Since: version 1.0.0

Definition at line 21059 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::binary ( const typename binary_t::container_type & init )

inlinestatic

explicitly create a binary array (without subtype)

Creates a JSON binary array value from a given binary container. Binary values are part of various binary formats, such as CBOR, MessagePack, and BSON. This constructor is used to create a value for serialization to those formats.

Note: Note, this function exists because of the difficulty in correctly specifying the correct template overload in the standard value ctor, as both JSON arrays and JSON binary arrays are backed with some form of a std::vector. Because JSON binary arrays are a non-standard extension it was decided that it would be best to prevent automatic initialization of a binary array type, for backwards compatibility and so it does not happen on accident.

Parameters

[in] init container containing bytes to use as binary type

Returns: JSON binary array value

Linear in the size of init.

Strong guarantee: if an exception is thrown, there are no changes to any JSON value.

Since: version 3.8.0

Definition at line 18250 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::binary	(	const typename binary_t::container_type &	init,
		std::uint8_t	subtype
	)

inlinestatic

explicitly create a binary array (with subtype)

Creates a JSON binary array value from a given binary container. Binary values are part of various binary formats, such as CBOR, MessagePack, and BSON. This constructor is used to create a value for serialization to those formats.

Note: Note, this function exists because of the difficulty in correctly specifying the correct template overload in the standard value ctor, as both JSON arrays and JSON binary arrays are backed with some form of a std::vector. Because JSON binary arrays are a non-standard extension it was decided that it would be best to prevent automatic initialization of a binary array type, for backwards compatibility and so it does not happen on accident.

Parameters

[in]	init	container containing bytes to use as binary type
[in]	subtype	subtype to use in MessagePack and BSON

Returns: JSON binary array value

Linear in the size of init.

Strong guarantee: if an exception is thrown, there are no changes to any JSON value.

Since: version 3.8.0

Definition at line 18287 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::binary ( typename binary_t::container_type && init )

inlinestatic

explicitly create a binary array (without subtype)

Creates a JSON binary array value from a given binary container. Binary values are part of various binary formats, such as CBOR, MessagePack, and BSON. This constructor is used to create a value for serialization to those formats.

Note: Note, this function exists because of the difficulty in correctly specifying the correct template overload in the standard value ctor, as both JSON arrays and JSON binary arrays are backed with some form of a std::vector. Because JSON binary arrays are a non-standard extension it was decided that it would be best to prevent automatic initialization of a binary array type, for backwards compatibility and so it does not happen on accident.

Parameters

[in] init container containing bytes to use as binary type

Returns: JSON binary array value

Linear in the size of init.

Strong guarantee: if an exception is thrown, there are no changes to any JSON value.

Since: version 3.8.0

Definition at line 18297 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::binary	(	typename binary_t::container_type &&	init,
		std::uint8_t	subtype
	)

inlinestatic

explicitly create a binary array (with subtype)

Creates a JSON binary array value from a given binary container. Binary values are part of various binary formats, such as CBOR, MessagePack, and BSON. This constructor is used to create a value for serialization to those formats.

Note: Note, this function exists because of the difficulty in correctly specifying the correct template overload in the standard value ctor, as both JSON arrays and JSON binary arrays are backed with some form of a std::vector. Because JSON binary arrays are a non-standard extension it was decided that it would be best to prevent automatic initialization of a binary array type, for backwards compatibility and so it does not happen on accident.

Parameters

[in]	init	container containing bytes to use as binary type
[in]	subtype	subtype to use in MessagePack and BSON

Returns: JSON binary array value

Linear in the size of init.

Strong guarantee: if an exception is thrown, there are no changes to any JSON value.

Since: version 3.8.0

Definition at line 18307 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

const_iterator nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::cbegin ( ) const

inlinenoexcept

returns a const iterator to the first element

Returns a const iterator to the first element.

Illustration from cppreference.com

Returns: const iterator to the first element

Constant.

This function helps basic_json satisfying the Container requirements:

The complexity is constant.
Has the semantics of const_cast<const basic_json&>(*this).begin().

{The following code shows an example for cbegin().,cbegin}

See also: begin() – returns an iterator to the beginning; end() – returns an iterator to the end; cend() – returns a const iterator to the end

Since: version 1.0.0

Definition at line 21089 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

const_iterator nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::cend ( ) const

inlinenoexcept

returns a const iterator to one past the last element

Returns a const iterator to one past the last element.

Illustration from cppreference.com

Returns: const iterator one past the last element

Constant.

This function helps basic_json satisfying the Container requirements:

The complexity is constant.
Has the semantics of const_cast<const basic_json&>(*this).end().

{The following code shows an example for cend().,cend}

See also: end() – returns an iterator to the end; begin() – returns an iterator to the beginning; cbegin() – returns a const iterator to the beginning

Since: version 1.0.0

Definition at line 21160 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::clear ( )

inlinenoexcept

clears the contents

Clears the content of a JSON value and resets it to the default value as if basic_json(value_t) would have been called with the current value type from type():

Value type	initial value
null	`null`
boolean	`false`
string	`""`
number	`0`
binary	An empty byte vector
object	`{}`
array	`[]`

Postcondition: Has the same effect as calling
*this = basic_json(type());

{The example below shows the effect of clear() to different JSON types.,clear}

Linear in the size of the JSON value.

All iterators, pointers and references related to this container are invalidated.

No-throw guarantee: this function never throws exceptions.

See also: basic_json(value_t) – constructor that creates an object with the same value than calling clear()

Since: version 1.0.0

Definition at line 21719 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename KeyT , typename std::enable_if< !std::is_same< typename std::decay< KeyT >::type, json_pointer >::value, int >::type = 0>

bool nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::contains ( KeyT && key ) const

inline

check the existence of an element in a JSON object

Check whether an element exists in a JSON object with key equivalent to key. If the element is not found or the JSON value is not an object, false is returned.

Note: This method always returns false when executed on a JSON type that is not an object.

Parameters

[in] key key value to check its existence.

Returns: true if an element with specified key exists. If no such element with such key is found or the JSON value is not an object, false is returned.

Logarithmic in the size of the JSON object.

{The following code shows an example for contains().,contains}

See also: find(KeyT&&) – returns an iterator to an object element; contains(const json_pointer&) const – checks the existence for a JSON pointer

Since: version 3.6.0

Definition at line 20979 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

bool nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::contains ( const json_pointer & ptr ) const

inline

check the existence of an element in a JSON object given a JSON pointer

Check whether the given JSON pointer ptr can be resolved in the current JSON value.

Note: This method can be executed on any JSON value type.

Parameters

[in] ptr JSON pointer to check its existence.

Returns: true if the JSON pointer can be resolved to a stored value, false otherwise.

Postcondition: If j.contains(ptr) returns true, it is safe to call j[ptr].

Exceptions

parse_error.106	if an array index begins with '0'
parse_error.109	if an array index was not a number

Logarithmic in the size of the JSON object.

{The following code shows an example for contains().,contains_json_pointer}

See also: contains(KeyT &&) const – checks the existence of a key

Since: version 3.7.0

Definition at line 21010 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename KeyT >

size_type nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::count ( KeyT && key ) const

inline

returns the number of occurrences of a key in a JSON object

Returns the number of elements with key key. If ObjectType is the default std::map type, the return value will always be 0 (key was not found) or 1 (key was found).

Note: This method always returns 0 when executed on a JSON type that is not an object.

Parameters

[in] key key value of the element to count

Returns: Number of elements with key key. If the JSON value is not an object, the return value will be 0.

Logarithmic in the size of the JSON object.

{The example shows how count() is used.,count}

Since: version 1.0.0

Definition at line 20946 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

const_reverse_iterator nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::crbegin ( ) const

inlinenoexcept

returns a const reverse iterator to the last element

Returns a const iterator to the reverse-beginning; that is, the last element.

Illustration from cppreference.com

Constant.

This function helps basic_json satisfying the ReversibleContainer requirements:

The complexity is constant.
Has the semantics of const_cast<const basic_json&>(*this).rbegin().

{The following code shows an example for crbegin().,crbegin}

See also: rbegin() – returns a reverse iterator to the beginning; rend() – returns a reverse iterator to the end; crend() – returns a const reverse iterator to the end

Since: version 1.0.0

Definition at line 21264 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename T , typename... Args>

static JSON_HEDLEY_RETURNS_NON_NULL T* nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::create ( Args &&... args )

inlinestaticprivate

helper for exception-safe object creation

Definition at line 17487 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

const_reverse_iterator nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::crend ( ) const

inlinenoexcept

returns a const reverse iterator to one before the first

Returns a const reverse iterator to the reverse-end; that is, one before the first element.

Illustration from cppreference.com

Constant.

This function helps basic_json satisfying the ReversibleContainer requirements:

The complexity is constant.
Has the semantics of const_cast<const basic_json&>(*this).rend().

{The following code shows an example for crend().,crend}

See also: rend() – returns a reverse iterator to the end; rbegin() – returns a reverse iterator to the beginning; crbegin() – returns a const reverse iterator to the beginning

Since: version 1.0.0

Definition at line 21293 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::destroy ( value_t t )

inlineprivatenoexcept

Definition at line 17692 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::diff	(	const basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType > &	source,
		const basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType > &	target,
		const std::string &	path = `""`
	)

inlinestatic

creates a diff as a JSON patch

Creates a JSON Patch so that value source can be changed into the value target by calling patch function.

Invariant: For two JSON values source and target, the following code yields always true:
source.patch(diff(source, target)) == target;

Note: Currently, only remove, add, and replace operations are generated.

Parameters

[in]	source	JSON value to compare from
[in]	target	JSON value to compare against
[in]	path	helper value to create JSON pointers

Returns: a JSON patch to convert the source to target

Linear in the lengths of source and target.

{The following code shows how a JSON patch is created as a diff for two JSON values.,diff}

See also: patch – apply a JSON patch; merge_patch – apply a JSON Merge Patch; RFC 6902 (JSON Patch)

Since: version 2.0.0

Definition at line 25041 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

string_t nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::dump	(	const int	indent = `-1`,
		const char	indent_char = `' '`,
		const bool	ensure_ascii = `false`,
		const error_handler_t	error_handler = `error_handler_t::strict`
	)		const

inline

serialization

Serialization function for JSON values. The function tries to mimic Python's json.dumps() function, and currently supports its indent and ensure_ascii parameters.

Parameters

[in]	indent	If indent is nonnegative, then array elements and object members will be pretty-printed with that indent level. An indent level of `0` will only insert newlines. `-1` (the default) selects the most compact representation.
[in]	indent_char	The character to use for indentation if indent is greater than `0`. The default is (space).
[in]	ensure_ascii	If ensure_ascii is true, all non-ASCII characters in the output are escaped with `\uXXXX` sequences, and the result consists of ASCII characters only.
[in]	error_handler	how to react on decoding errors; there are three possible values: `strict` (throws and exception in case a decoding error occurs; default), `replace` (replace invalid UTF-8 sequences with U+FFFD), and `ignore` (ignore invalid UTF-8 sequences during serialization; all bytes are copied to the output unchanged).

Returns: string containing the serialization of the JSON value

Exceptions

type_error.316 if a string stored inside the JSON value is not UTF-8 encoded and error_handler is set to strict

Note

Binary values are serialized as object containing two keys:

"bytes": an array of bytes as integers
"subtype": the subtype as integer or "null" if the binary has no subtype

Linear.

Strong guarantee: if an exception is thrown, there are no changes in the JSON value.

{The following example shows the effect of different indent\, indent_char\, and ensure_ascii parameters to the result of the serialization.,dump}

See also: https://docs.python.org/2/library/json.html#json.dump

Since: version 1.0.0; indentation character indent_char, option ensure_ascii and exceptions added in version 3.0.0; error handlers added in version 3.4.0; serialization of binary values added in version 3.8.0.

Definition at line 18842 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<class... Args>

std::pair<iterator, bool> nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::emplace ( Args &&... args )

inline

add an object to an object if key does not exist

Inserts a new element into a JSON object constructed in-place with the given args if there is no element with the key in the container. If the function is called on a JSON null value, an empty object is created before appending the value created from args.

Parameters

[in] args arguments to forward to a constructor of basic_json

Template Parameters

Args	compatible types to create a basic_json object

Returns: a pair consisting of an iterator to the inserted element, or the already-existing element if no insertion happened, and a bool denoting whether the insertion took place.

Exceptions

type_error.311 when called on a type other than JSON object or null; example: "cannot use emplace() with number"

Logarithmic in the size of the container, O(log(size())).

{The example shows how emplace() can be used to add elements to a JSON object. Note how the null value was silently converted to a JSON object. Further note how no value is added if there was already one value stored with the same key.,emplace}

Since: version 2.0.8

Definition at line 22037 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<class... Args>

reference nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::emplace_back ( Args &&... args )

inline

add an object to an array

Creates a JSON value from the passed parameters args to the end of the JSON value. If the function is called on a JSON null value, an empty array is created before appending the value created from args.

Parameters

[in] args arguments to forward to a constructor of basic_json

Template Parameters

Args	compatible types to create a basic_json object

Returns: reference to the inserted element

Exceptions

type_error.311 when called on a type other than JSON array or null; example: "cannot use emplace_back() with number"

Amortized constant.

{The example shows how push_back() can be used to add elements to a JSON array. Note how the null value was silently converted to a JSON array.,emplace_back}

Since: version 2.0.8, returns reference since 3.7.0

Definition at line 21984 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

bool nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::empty ( ) const

inlinenoexcept

checks whether the container is empty.

Checks if a JSON value has no elements (i.e. whether its size is 0).

Returns

The return value depends on the different types and is defined as follows:

Value type	return value
null	`true`
boolean	`false`
string	`false`
number	`false`
binary	`false`
object	result of function `object_t::empty()`
array	result of function `array_t::empty()`

{The following code uses empty() to check if a JSON object contains any elements.,empty}

Constant, as long as array_t and object_t satisfy the Container concept; that is, their empty() functions have constant complexity.

No changes.

No-throw guarantee: this function never throws exceptions.

Note: This function does not return whether a string stored as JSON value is empty - it returns whether the JSON container itself is empty which is false in the case of a string.

This function helps basic_json satisfying the Container requirements:

The complexity is constant.
Has the semantics of begin() == end().

See also: size() – returns the number of elements

Since: version 1.0.0

Definition at line 21504 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

iterator nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::end ( )

inlinenoexcept

returns an iterator to one past the last element

Returns an iterator to one past the last element.

Illustration from cppreference.com

Returns: iterator one past the last element

Constant.

This function helps basic_json satisfying the Container requirements:

The complexity is constant.

{The following code shows an example for end().,end}

See also: cend() – returns a const iterator to the end; begin() – returns an iterator to the beginning; cbegin() – returns a const iterator to the beginning

Since: version 1.0.0

Definition at line 21120 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

const_iterator nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::end ( ) const

inlinenoexcept

returns a const iterator to one past the last element

Returns a const iterator to one past the last element.

Illustration from cppreference.com

Returns: const iterator one past the last element

Constant.

This function helps basic_json satisfying the Container requirements:

The complexity is constant.
Has the semantics of const_cast<const basic_json&>(*this).end().

{The following code shows an example for cend().,cend}

See also: end() – returns an iterator to the end; begin() – returns an iterator to the beginning; cbegin() – returns a const iterator to the beginning

Since: version 1.0.0

Definition at line 21130 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<class IteratorType , typename std::enable_if< std::is_same< IteratorType, typename basic_json_t::iterator >::value||std::is_same< IteratorType, typename basic_json_t::const_iterator >::value, int >::type = 0>

IteratorType nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::erase ( IteratorType pos )

inline

remove element given an iterator

Removes the element specified by iterator pos. The iterator pos must be valid and dereferenceable. Thus the end() iterator (which is valid, but is not dereferenceable) cannot be used as a value for pos.

If called on a primitive type other than null, the resulting JSON value will be null.

Parameters

[in] pos iterator to the element to remove

Returns: Iterator following the last removed element. If the iterator pos refers to the last element, the end() iterator is returned.

Template Parameters

IteratorType an iterator or const_iterator

Postcondition: Invalidates iterators and references at or after the point of the erase, including the end() iterator.

Exceptions

type_error.307	if called on a `null` value; example: `"cannot use erase() with null"`
invalid_iterator.202	if called on an iterator which does not belong to the current JSON value; example: `"iterator does not fit current value"`
invalid_iterator.205	if called on a primitive type with invalid iterator (i.e., any iterator which is not `begin()`); example: `"iterator out of range"`

The complexity depends on the type:

objects: amortized constant
arrays: linear in distance between pos and the end of the container
strings and binary: linear in the length of the member
other types: constant

{The example shows the result of erase() for different JSON types.,erase__IteratorType}

See also: erase(IteratorType, IteratorType) – removes the elements in the given range; erase(const typename object_t::key_type&) – removes the element from an object at the given key; erase(const size_type) – removes the element from an array at the given index

Since: version 1.0.0

Definition at line 20599 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<class IteratorType , typename std::enable_if< std::is_same< IteratorType, typename basic_json_t::iterator >::value||std::is_same< IteratorType, typename basic_json_t::const_iterator >::value, int >::type = 0>

IteratorType nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::erase	(	IteratorType	first,
		IteratorType	last
	)

inline

remove elements given an iterator range

Removes the element specified by the range [first; last). The iterator first does not need to be dereferenceable if first == last: erasing an empty range is a no-op.

If called on a primitive type other than null, the resulting JSON value will be null.

Parameters

[in]	first	iterator to the beginning of the range to remove
[in]	last	iterator past the end of the range to remove

Returns: Iterator following the last removed element. If the iterator second refers to the last element, the end() iterator is returned.

Template Parameters

IteratorType an iterator or const_iterator

Postcondition: Invalidates iterators and references at or after the point of the erase, including the end() iterator.

Exceptions

type_error.307	if called on a `null` value; example: `"cannot use erase() with null"`
invalid_iterator.203	if called on iterators which does not belong to the current JSON value; example: `"iterators do not fit current value"`
invalid_iterator.204	if called on a primitive type with invalid iterators (i.e., if `first != begin()` and `last != end()`); example: `"iterators out of range"`

The complexity depends on the type:

objects: log(size()) + std::distance(first, last)
arrays: linear in the distance between first and last, plus linear in the distance between last and end of the container
strings and binary: linear in the length of the member
other types: constant

{The example shows the result of erase() for different JSON types.,erase__IteratorType_IteratorType}

See also: erase(IteratorType) – removes the element at a given position; erase(const typename object_t::key_type&) – removes the element from an object at the given key; erase(const size_type) – removes the element from an array at the given index

Since: version 1.0.0

Definition at line 20712 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

size_type nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::erase ( const typename object_t::key_type & key )

inline

remove element from a JSON object given a key

Removes elements from a JSON object with the key value key.

Parameters

[in] key value of the elements to remove

Returns: Number of elements removed. If ObjectType is the default std::map type, the return value will always be 0 (key was not found) or 1 (key was found).

Postcondition: References and iterators to the erased elements are invalidated. Other references and iterators are not affected.

Exceptions

type_error.307 when called on a type other than JSON object; example: "cannot use erase() with null"

log(size()) + count(key)

{The example shows the effect of erase().,erase__key_type}

See also: erase(IteratorType) – removes the element at a given position; erase(IteratorType, IteratorType) – removes the elements in the given range; erase(const size_type) – removes the element from an array at the given index

Since: version 1.0.0

Definition at line 20807 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::erase ( const size_type idx )

inline

remove element from a JSON array given an index

Removes element from a JSON array at the index idx.

Parameters

[in] idx index of the element to remove

Exceptions

type_error.307	when called on a type other than JSON object; example: `"cannot use erase() with null"`
out_of_range.401	when `idx >= size()`; example: `"array index 17 is out of range"`

Linear in distance between idx and the end of the container.

{The example shows the effect of erase().,erase__size_type}

See also: erase(IteratorType) – removes the element at a given position; erase(IteratorType, IteratorType) – removes the elements in the given range; erase(const typename object_t::key_type&) – removes the element from an object at the given key

Since: version 1.0.0

Definition at line 20842 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename KeyT >

iterator nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::find ( KeyT && key )

inline

find an element in a JSON object

Finds an element in a JSON object with key equivalent to key. If the element is not found or the JSON value is not an object, end() is returned.

Note: This method always returns end() when executed on a JSON type that is not an object.

Parameters

[in] key key value of the element to search for.

Returns: Iterator to an element with key equivalent to key. If no such element is found or the JSON value is not an object, past-the-end (see end()) iterator is returned.

Logarithmic in the size of the JSON object.

{The example shows how find() is used.,find__key_type}

See also: contains(KeyT&&) const – checks whether a key exists

Since: version 1.0.0

Definition at line 20895 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename KeyT >

const_iterator nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::find ( KeyT && key ) const

inline

find an element in a JSON object

find an element in a JSON object Finds an element in a JSON object with key equivalent to key. If the element is not found or the JSON value is not an object, end() is returned.

Note: This method always returns end() when executed on a JSON type that is not an object.

Parameters

[in] key key value of the element to search for.

Returns: Iterator to an element with key equivalent to key. If no such element is found or the JSON value is not an object, past-the-end (see end()) iterator is returned.

Logarithmic in the size of the JSON object.

{The example shows how find() is used.,find__key_type}

See also: contains(KeyT&&) const – checks whether a key exists

Since: version 1.0.0

Definition at line 20912 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::flatten ( ) const

inline

return flattened JSON value

The function creates a JSON object whose keys are JSON pointers (see RFC 6901) and whose values are all primitive. The original JSON value can be restored using the unflatten() function.

Returns: an object that maps JSON pointers to primitive values

Note: Empty objects and arrays are flattened to null and will not be reconstructed correctly by the unflatten() function.

Linear in the size the JSON value.

{The following code shows how a JSON object is flattened to an object whose keys consist of JSON pointers.,flatten}

See also: unflatten() for the reverse function

Since: version 2.0.0

Definition at line 24647 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename InputType >

static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::from_bson	(	InputType &&	i,
		const bool	strict = `true`,
		const bool	allow_exceptions = `true`
	)

inlinestatic

Create a JSON value from an input in BSON format.

Deserializes a given input i to a JSON value using the BSON (Binary JSON) serialization format.

The library maps BSON record types to JSON value types as follows:

BSON type	BSON marker byte	JSON value type
double	0x01	number_float
string	0x02	string
document	0x03	object
array	0x04	array
binary	0x05	binary
undefined	0x06	still unsupported
ObjectId	0x07	still unsupported
boolean	0x08	boolean
UTC Date-Time	0x09	still unsupported
null	0x0A	null
Regular Expr.	0x0B	still unsupported
DB Pointer	0x0C	still unsupported
JavaScript Code	0x0D	still unsupported
Symbol	0x0E	still unsupported
JavaScript Code	0x0F	still unsupported
int32	0x10	number_integer
Timestamp	0x11	still unsupported
128-bit decimal float	0x13	still unsupported
Max Key	0x7F	still unsupported
Min Key	0xFF	still unsupported

Warning: The mapping is incomplete. The unsupported mappings are indicated in the table above.

Parameters

[in]	i	an input in BSON format convertible to an input adapter
[in]	strict	whether to expect the input to be consumed until EOF (true by default)
[in]	allow_exceptions	whether to throw exceptions in case of a parse error (optional, true by default)

Returns: deserialized JSON value; in case of a parse error and allow_exceptions set to false, the return value will be value_t::discarded.

Exceptions

parse_error.114 if an unsupported BSON record type is encountered

Linear in the size of the input i.

{The example shows the deserialization of a byte vector in BSON format to a JSON value.,from_bson}

See also: http://bsonspec.org/spec.html; to_bson(const basic_json&) for the analogous serialization; from_cbor(detail::input_adapter&&, const bool, const bool, const cbor_tag_handler_t) for the related CBOR format; from_msgpack(detail::input_adapter&&, const bool, const bool) for the related MessagePack format; from_ubjson(detail::input_adapter&&, const bool, const bool) for the related UBJSON format

Definition at line 24415 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename IteratorType >

static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::from_bson	(	IteratorType	first,
		IteratorType	last,
		const bool	strict = `true`,
		const bool	allow_exceptions = `true`
	)

inlinestatic

Definition at line 24431 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename T >

static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::from_bson	(	const T *	ptr,
		std::size_t	len,
		const bool	strict = `true`,
		const bool	allow_exceptions = `true`
	)

inlinestatic

Definition at line 24445 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::from_bson	(	detail::span_input_adapter &&	i,
		const bool	strict = `true`,
		const bool	allow_exceptions = `true`
	)

inlinestatic

Definition at line 24454 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename InputType >

static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::from_cbor	(	InputType &&	i,
		const bool	strict = `true`,
		const bool	allow_exceptions = `true`,
		const cbor_tag_handler_t	tag_handler = `cbor_tag_handler_t::error`
	)

inlinestatic

create a JSON value from an input in CBOR format

Deserializes a given input i to a JSON value using the CBOR (Concise Binary Object Representation) serialization format.

The library maps CBOR types to JSON value types as follows:

CBOR type	JSON value type	first byte
Integer	number_unsigned	0x00..0x17
Unsigned integer	number_unsigned	0x18
Unsigned integer	number_unsigned	0x19
Unsigned integer	number_unsigned	0x1A
Unsigned integer	number_unsigned	0x1B
Negative integer	number_integer	0x20..0x37
Negative integer	number_integer	0x38
Negative integer	number_integer	0x39
Negative integer	number_integer	0x3A
Negative integer	number_integer	0x3B
Byte string	binary	0x40..0x57
Byte string	binary	0x58
Byte string	binary	0x59
Byte string	binary	0x5A
Byte string	binary	0x5B
UTF-8 string	string	0x60..0x77
UTF-8 string	string	0x78
UTF-8 string	string	0x79
UTF-8 string	string	0x7A
UTF-8 string	string	0x7B
UTF-8 string	string	0x7F
array	array	0x80..0x97
array	array	0x98
array	array	0x99
array	array	0x9A
array	array	0x9B
array	array	0x9F
map	object	0xA0..0xB7
map	object	0xB8
map	object	0xB9
map	object	0xBA
map	object	0xBB
map	object	0xBF
False	`false`	0xF4
True	`true`	0xF5
Null	`null`	0xF6
Half-Precision Float	number_float	0xF9
Single-Precision Float	number_float	0xFA
Double-Precision Float	number_float	0xFB

Warning

The mapping is incomplete in the sense that not all CBOR types can be converted to a JSON value. The following CBOR types are not supported and will yield parse errors (parse_error.112):

date/time (0xC0..0xC1)
bignum (0xC2..0xC3)
decimal fraction (0xC4)
bigfloat (0xC5)
expected conversions (0xD5..0xD7)
simple values (0xE0..0xF3, 0xF8)
undefined (0xF7)

CBOR allows map keys of any type, whereas JSON only allows strings as keys in object values. Therefore, CBOR maps with keys other than UTF-8 strings are rejected (parse_error.113).

Note: Any CBOR output created to_cbor can be successfully parsed by from_cbor.

Parameters

[in]	i	an input in CBOR format convertible to an input adapter
[in]	strict	whether to expect the input to be consumed until EOF (true by default)
[in]	allow_exceptions	whether to throw exceptions in case of a parse error (optional, true by default)
[in]	tag_handler	how to treat CBOR tags (optional, error by default)

Returns: deserialized JSON value; in case of a parse error and allow_exceptions set to false, the return value will be value_t::discarded.

Exceptions

parse_error.110	if the given input ends prematurely or the end of file was not reached when strict was set to true
parse_error.112	if unsupported features from CBOR were used in the given input v or if the input is not valid CBOR
parse_error.113	if a string was expected as map key, but not found

Linear in the size of the input i.

{The example shows the deserialization of a byte vector in CBOR format to a JSON value.,from_cbor}

See also: http://cbor.io; to_cbor(const basic_json&) for the analogous serialization; from_msgpack(detail::input_adapter&&, const bool, const bool) for the related MessagePack format; from_ubjson(detail::input_adapter&&, const bool, const bool) for the related UBJSON format

Since: version 2.0.9; parameter start_index since 2.1.1; changed to consume input adapters, removed start_index parameter, and added strict parameter since 3.0.0; added allow_exceptions parameter since 3.2.0; added tag_handler parameter since 3.9.0.

Definition at line 24043 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename IteratorType >

static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::from_cbor	(	IteratorType	first,
		IteratorType	last,
		const bool	strict = `true`,
		const bool	allow_exceptions = `true`,
		const cbor_tag_handler_t	tag_handler = `cbor_tag_handler_t::error`
	)

inlinestatic

Definition at line 24060 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename T >

static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::from_cbor	(	const T *	ptr,
		std::size_t	len,
		const bool	strict = `true`,
		const bool	allow_exceptions = `true`,
		const cbor_tag_handler_t	tag_handler = `cbor_tag_handler_t::error`
	)

inlinestatic

Definition at line 24075 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::from_cbor	(	detail::span_input_adapter &&	i,
		const bool	strict = `true`,
		const bool	allow_exceptions = `true`,
		const cbor_tag_handler_t	tag_handler = `cbor_tag_handler_t::error`
	)

inlinestatic

Definition at line 24086 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename InputType >

static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::from_msgpack	(	InputType &&	i,
		const bool	strict = `true`,
		const bool	allow_exceptions = `true`
	)

inlinestatic

create a JSON value from an input in MessagePack format

Deserializes a given input i to a JSON value using the MessagePack serialization format.

The library maps MessagePack types to JSON value types as follows:

MessagePack type	JSON value type	first byte
positive fixint	number_unsigned	0x00..0x7F
fixmap	object	0x80..0x8F
fixarray	array	0x90..0x9F
fixstr	string	0xA0..0xBF
nil	`null`	0xC0
false	`false`	0xC2
true	`true`	0xC3
float 32	number_float	0xCA
float 64	number_float	0xCB
uint 8	number_unsigned	0xCC
uint 16	number_unsigned	0xCD
uint 32	number_unsigned	0xCE
uint 64	number_unsigned	0xCF
int 8	number_integer	0xD0
int 16	number_integer	0xD1
int 32	number_integer	0xD2
int 64	number_integer	0xD3
str 8	string	0xD9
str 16	string	0xDA
str 32	string	0xDB
array 16	array	0xDC
array 32	array	0xDD
map 16	object	0xDE
map 32	object	0xDF
bin 8	binary	0xC4
bin 16	binary	0xC5
bin 32	binary	0xC6
ext 8	binary	0xC7
ext 16	binary	0xC8
ext 32	binary	0xC9
fixext 1	binary	0xD4
fixext 2	binary	0xD5
fixext 4	binary	0xD6
fixext 8	binary	0xD7
fixext 16	binary	0xD8
negative fixint	number_integer	0xE0-0xFF

Note: Any MessagePack output created to_msgpack can be successfully parsed by from_msgpack.

Parameters

[in]	i	an input in MessagePack format convertible to an input adapter
[in]	strict	whether to expect the input to be consumed until EOF (true by default)
[in]	allow_exceptions	whether to throw exceptions in case of a parse error (optional, true by default)

Returns: deserialized JSON value; in case of a parse error and allow_exceptions set to false, the return value will be value_t::discarded.

Exceptions

parse_error.110	if the given input ends prematurely or the end of file was not reached when strict was set to true
parse_error.112	if unsupported features from MessagePack were used in the given input i or if the input is not valid MessagePack
parse_error.113	if a string was expected as map key, but not found

Linear in the size of the input i.

{The example shows the deserialization of a byte vector in MessagePack format to a JSON value.,from_msgpack}

See also: http://msgpack.org; to_msgpack(const basic_json&) for the analogous serialization; from_cbor(detail::input_adapter&&, const bool, const bool, const cbor_tag_handler_t) for the related CBOR format; from_ubjson(detail::input_adapter&&, const bool, const bool) for the related UBJSON format; from_bson(detail::input_adapter&&, const bool, const bool) for the related BSON format

Since: version 2.0.9; parameter start_index since 2.1.1; changed to consume input adapters, removed start_index parameter, and added strict parameter since 3.0.0; added allow_exceptions parameter since 3.2.0

Definition at line 24186 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename IteratorType >

static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::from_msgpack	(	IteratorType	first,
		IteratorType	last,
		const bool	strict = `true`,
		const bool	allow_exceptions = `true`
	)

inlinestatic

Definition at line 24202 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename T >

static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::from_msgpack	(	const T *	ptr,
		std::size_t	len,
		const bool	strict = `true`,
		const bool	allow_exceptions = `true`
	)

inlinestatic

Definition at line 24217 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::from_msgpack	(	detail::span_input_adapter &&	i,
		const bool	strict = `true`,
		const bool	allow_exceptions = `true`
	)

inlinestatic

Definition at line 24226 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename InputType >

static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::from_ubjson	(	InputType &&	i,
		const bool	strict = `true`,
		const bool	allow_exceptions = `true`
	)

inlinestatic

create a JSON value from an input in UBJSON format

Deserializes a given input i to a JSON value using the UBJSON (Universal Binary JSON) serialization format.

The library maps UBJSON types to JSON value types as follows:

UBJSON type	JSON value type	marker
no-op	no value, next value is read	`N`
null	`null`	`Z`
false	`false`	`F`
true	`true`	`T`
float32	number_float	`d`
float64	number_float	`D`
uint8	number_unsigned	`U`
int8	number_integer	`i`
int16	number_integer	`I`
int32	number_integer	`l`
int64	number_integer	`L`
high-precision number	number_integer, number_unsigned, or number_float - depends on number string	'H'
string	string	`S`
char	string	`C`
array	array (optimized values are supported)	`[`
object	object (optimized values are supported)	`{`

Note: The mapping is complete in the sense that any UBJSON value can be converted to a JSON value.

Parameters

[in]	i	an input in UBJSON format convertible to an input adapter
[in]	strict	whether to expect the input to be consumed until EOF (true by default)
[in]	allow_exceptions	whether to throw exceptions in case of a parse error (optional, true by default)

Returns: deserialized JSON value; in case of a parse error and allow_exceptions set to false, the return value will be value_t::discarded.

Exceptions

parse_error.110	if the given input ends prematurely or the end of file was not reached when strict was set to true
parse_error.112	if a parse error occurs
parse_error.113	if a string could not be parsed successfully

Linear in the size of the input i.

{The example shows the deserialization of a byte vector in UBJSON format to a JSON value.,from_ubjson}

See also: http://ubjson.org; to_ubjson(const basic_json&, const bool, const bool) for the analogous serialization; from_cbor(detail::input_adapter&&, const bool, const bool, const cbor_tag_handler_t) for the related CBOR format; from_msgpack(detail::input_adapter&&, const bool, const bool) for the related MessagePack format; from_bson(detail::input_adapter&&, const bool, const bool) for the related BSON format

Since: version 3.1.0; added allow_exceptions parameter since 3.2.0

Definition at line 24302 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename IteratorType >

static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::from_ubjson	(	IteratorType	first,
		IteratorType	last,
		const bool	strict = `true`,
		const bool	allow_exceptions = `true`
	)

inlinestatic

Definition at line 24318 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename T >

static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::from_ubjson	(	const T *	ptr,
		std::size_t	len,
		const bool	strict = `true`,
		const bool	allow_exceptions = `true`
	)

inlinestatic

Definition at line 24332 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::from_ubjson	(	detail::span_input_adapter &&	i,
		const bool	strict = `true`,
		const bool	allow_exceptions = `true`
	)

inlinestatic

Definition at line 24341 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

reference nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::front ( )

inline

access the first element

Returns a reference to the first element in the container. For a JSON container c, the expression c.front() is equivalent to *c.begin().

Returns: In case of a structured type (array or object), a reference to the first element is returned. In case of number, string, boolean, or binary values, a reference to the value is returned.

Constant.

Precondition: The JSON value must not be null (would throw std::out_of_range) or an empty array or object (undefined behavior, guarded by assertions).

Postcondition: The JSON value remains unchanged.

Exceptions

invalid_iterator.214 when called on null value

{The following code shows an example for front().,front}

See also: back() – access the last element

Since: version 1.0.0

Definition at line 20488 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

const_reference nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::front ( ) const

inline

access the first element

Returns a reference to the first element in the container. For a JSON container c, the expression c.front() is equivalent to *c.begin().

Returns: In case of a structured type (array or object), a reference to the first element is returned. In case of number, string, boolean, or binary values, a reference to the value is returned.

Constant.

Precondition: The JSON value must not be null (would throw std::out_of_range) or an empty array or object (undefined behavior, guarded by assertions).

Postcondition: The JSON value remains unchanged.

Exceptions

invalid_iterator.214 when called on null value

{The following code shows an example for front().,front}

See also: back() – access the last element

Since: version 1.0.0

Definition at line 20496 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename BasicJsonType , detail::enable_if_t< std::is_same< typename std::remove_const< BasicJsonType >::type, basic_json_t >::value, int > = 0>

basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::get ( ) const

inline

get special-case overload

This overloads avoids a lot of template boilerplate, it can be seen as the identity method

Template Parameters

BasicJsonType == basic_json

Returns: a copy of *this

Constant.

Since: version 2.1.0

Definition at line 19419 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename BasicJsonType , detail::enable_if_t< !std::is_same< BasicJsonType, basic_json >::value &&detail::is_basic_json< BasicJsonType >::value, int > = 0>

BasicJsonType nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::get ( ) const

inline

get special-case overload

This overloads converts the current basic_json in a different basic_json type

Template Parameters

BasicJsonType == basic_json

Returns: a copy of *this, converted into

Template Parameters

BasicJsonType Depending on the implementation of the called from_json() method.

Since: version 3.2.0

Definition at line 19442 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename ValueTypeCV , typename ValueType = detail::uncvref_t<ValueTypeCV>, detail::enable_if_t< !detail::is_basic_json< ValueType >::value &&detail::has_from_json< basic_json_t, ValueType >::value &&!detail::has_non_default_from_json< basic_json_t, ValueType >::value, int > = 0>

ValueType nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::get ( ) const

inlinenoexcept

get a value (explicit)

Explicit type conversion between the JSON value and a compatible value which is CopyConstructible and DefaultConstructible. The value is converted by calling the json_serializer<ValueType> from_json() method.

The function is equivalent to executing

ValueType ret;
JSONSerializer<ValueType>::from_json(*this, ret);
return ret;

This overloads is chosen if:

ValueType is not basic_json,
json_serializer<ValueType> has a from_json() method of the form void from_json(const basic_json&, ValueType&), and
json_serializer<ValueType> does not have a from_json() method of the form ValueType from_json(const basic_json&)

Template Parameters

ValueTypeCV	the provided value type
ValueType	the returned value type

Returns: copy of the JSON value, converted to ValueType

Exceptions

what	json_serializer<ValueType> `from_json()` method throws

{The example below shows several conversions from JSON values to other types. There a few things to note: (1) Floating-point numbers can be converted to integers\, (2) A JSON array can be converted to a standard std::vector<short>\, (3) A JSON object can be converted to C++ associative containers such as std::unordered_map<std::string\, json>.,get__ValueType_const}

Since: version 2.1.0

Definition at line 19492 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename ValueTypeCV , typename ValueType = detail::uncvref_t<ValueTypeCV>, detail::enable_if_t< !std::is_same< basic_json_t, ValueType >::value &&detail::has_non_default_from_json< basic_json_t, ValueType >::value, int > = 0>

ValueType nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::get ( ) const

inlinenoexcept

get a value (explicit); special case

Explicit type conversion between the JSON value and a compatible value which is not CopyConstructible and not DefaultConstructible. The value is converted by calling the json_serializer<ValueType> from_json() method.

The function is equivalent to executing

return JSONSerializer<ValueTypeCV>::from_json(*this);

This overloads is chosen if:

ValueType is not basic_json and
json_serializer<ValueType> has a from_json() method of the form ValueType from_json(const basic_json&)

Note: If json_serializer<ValueType> has both overloads of from_json(), this one is chosen.

Template Parameters

ValueTypeCV	the provided value type
ValueType	the returned value type

Returns: copy of the JSON value, converted to ValueType

Exceptions

what	json_serializer<ValueType> `from_json()` method throws

Since: version 2.1.0

Definition at line 19543 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename PointerType , typename std::enable_if< std::is_pointer< PointerType >::value, int >::type = 0>

auto nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::get ( ) -> decltype(std::declval<basic_json_t&>().template get_ptr<PointerType>())

inlinenoexcept

get a pointer value (explicit)

Explicit pointer access to the internally stored JSON value. No copies are made.

Warning: The pointer becomes invalid if the underlying JSON object changes.

Template Parameters

PointerType pointer type; must be a pointer to array_t, object_t, string_t, boolean_t, number_integer_t, number_unsigned_t, or number_float_t.

Returns: pointer to the internally stored JSON value if the requested pointer type PointerType fits to the JSON value; nullptr otherwise

Constant.

{The example below shows how pointers to internal values of a JSON value can be requested. Note that no type conversions are made and a nullptr is returned if the value and the requested pointer type does not match.,get__PointerType}

See also: get_ptr() for explicit pointer-member access

Since: version 1.0.0

Definition at line 19698 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename PointerType , typename std::enable_if< std::is_pointer< PointerType >::value, int >::type = 0>

constexpr auto nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::get ( ) const -> decltype(std::declval<const basic_json_t&>().template get_ptr<PointerType>())

inlinenoexcept

get a pointer value (explicit)

get a pointer value (explicit) Explicit pointer access to the internally stored JSON value. No copies are made.

Warning: The pointer becomes invalid if the underlying JSON object changes.

Template Parameters

PointerType pointer type; must be a pointer to array_t, object_t, string_t, boolean_t, number_integer_t, number_unsigned_t, or number_float_t.

Returns: pointer to the internally stored JSON value if the requested pointer type PointerType fits to the JSON value; nullptr otherwise

Constant.

{The example below shows how pointers to internal values of a JSON value can be requested. Note that no type conversions are made and a nullptr is returned if the value and the requested pointer type does not match.,get__PointerType}

See also: get_ptr() for explicit pointer-member access

Since: version 1.0.0

Definition at line 19710 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

static allocator_type nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::get_allocator ( )

inlinestatic

returns the allocator associated with the container

Definition at line 16880 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

binary_t& nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::get_binary ( )

inline

Returns: reference to the binary value

Exceptions

type_error.302 if the value is not binary

See also: is_binary() to check if the value is binary

Since: version 3.8.0

Definition at line 19818 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

const binary_t& nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::get_binary ( ) const

inline

Returns: reference to the binary value

Exceptions

type_error.302 if the value is not binary

See also: is_binary() to check if the value is binary

Since: version 3.8.0

Definition at line 19829 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

boolean_t nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::get_impl ( boolean_t * ) const

inlineprivate

get a boolean (explicit)

Definition at line 19266 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

object_t* nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::get_impl_ptr ( object_t * )

inlineprivatenoexcept

get a pointer to the value (object)

Definition at line 19277 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

constexpr const object_t* nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::get_impl_ptr ( const object_t * ) const

inlineprivatenoexcept

get a pointer to the value (object)

Definition at line 19283 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

array_t* nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::get_impl_ptr ( array_t * )

inlineprivatenoexcept

get a pointer to the value (array)

Definition at line 19289 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

constexpr const array_t* nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::get_impl_ptr ( const array_t * ) const

inlineprivatenoexcept

get a pointer to the value (array)

Definition at line 19295 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

string_t* nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::get_impl_ptr ( string_t * )

inlineprivatenoexcept

get a pointer to the value (string)

Definition at line 19301 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

constexpr const string_t* nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::get_impl_ptr ( const string_t * ) const

inlineprivatenoexcept

get a pointer to the value (string)

Definition at line 19307 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

boolean_t* nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::get_impl_ptr ( boolean_t * )

inlineprivatenoexcept

get a pointer to the value (boolean)

Definition at line 19313 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

constexpr const boolean_t* nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::get_impl_ptr ( const boolean_t * ) const

inlineprivatenoexcept

get a pointer to the value (boolean)

Definition at line 19319 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

number_integer_t* nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::get_impl_ptr ( number_integer_t * )

inlineprivatenoexcept

get a pointer to the value (integer number)

Definition at line 19325 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

constexpr const number_integer_t* nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::get_impl_ptr ( const number_integer_t * ) const

inlineprivatenoexcept

get a pointer to the value (integer number)

Definition at line 19331 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

number_unsigned_t* nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::get_impl_ptr ( number_unsigned_t * )

inlineprivatenoexcept

get a pointer to the value (unsigned number)

Definition at line 19337 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

constexpr const number_unsigned_t* nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::get_impl_ptr ( const number_unsigned_t * ) const

inlineprivatenoexcept

get a pointer to the value (unsigned number)

Definition at line 19343 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

number_float_t* nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::get_impl_ptr ( number_float_t * )

inlineprivatenoexcept

get a pointer to the value (floating-point number)

Definition at line 19349 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

constexpr const number_float_t* nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::get_impl_ptr ( const number_float_t * ) const

inlineprivatenoexcept

get a pointer to the value (floating-point number)

Definition at line 19355 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

binary_t* nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::get_impl_ptr ( binary_t * )

inlineprivatenoexcept

get a pointer to the value (binary)

Definition at line 19361 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

constexpr const binary_t* nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::get_impl_ptr ( const binary_t * ) const

inlineprivatenoexcept

get a pointer to the value (binary)

Definition at line 19367 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename PointerType , typename std::enable_if< std::is_pointer< PointerType >::value, int >::type = 0>

auto nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::get_ptr ( ) -> decltype(std::declval<basic_json_t&>().get_impl_ptr(std::declval<PointerType>()))

inlinenoexcept

get a pointer value (implicit)

Implicit pointer access to the internally stored JSON value. No copies are made.

Warning: Writing data to the pointee of the result yields an undefined state.

Template Parameters

PointerType pointer type; must be a pointer to array_t, object_t, string_t, boolean_t, number_integer_t, number_unsigned_t, or number_float_t. Enforced by a static assertion.

Returns: pointer to the internally stored JSON value if the requested pointer type PointerType fits to the JSON value; nullptr otherwise

Constant.

{The example below shows how pointers to internal values of a JSON value can be requested. Note that no type conversions are made and a nullptr is returned if the value and the requested pointer type does not match.,get_ptr}

Since: version 1.0.0

Definition at line 19650 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename PointerType , typename std::enable_if< std::is_pointer< PointerType >::value &&std::is_const< typename std::remove_pointer< PointerType >::type >::value, int >::type = 0>

constexpr auto nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::get_ptr ( ) const -> decltype(std::declval<const basic_json_t&>().get_impl_ptr(std::declval<PointerType>()))

inlinenoexcept

get a pointer value (implicit)

get a pointer value (implicit) Implicit pointer access to the internally stored JSON value. No copies are made.

Warning: Writing data to the pointee of the result yields an undefined state.

Template Parameters

PointerType pointer type; must be a pointer to array_t, object_t, string_t, boolean_t, number_integer_t, number_unsigned_t, or number_float_t. Enforced by a static assertion.

Returns: pointer to the internally stored JSON value if the requested pointer type PointerType fits to the JSON value; nullptr otherwise

Constant.

{The example below shows how pointers to internal values of a JSON value can be requested. Note that no type conversions are made and a nullptr is returned if the value and the requested pointer type does not match.,get_ptr}

Since: version 1.0.0

Definition at line 19663 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename ReferenceType , typename std::enable_if< std::is_reference< ReferenceType >::value, int >::type = 0>

ReferenceType nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::get_ref ( )

inline

get a reference value (implicit)

Implicit reference access to the internally stored JSON value. No copies are made.

Warning: Writing data to the referee of the result yields an undefined state.

Template Parameters

ReferenceType reference type; must be a reference to array_t, object_t, string_t, boolean_t, number_integer_t, or number_float_t. Enforced by static assertion.

Returns: reference to the internally stored JSON value if the requested reference type ReferenceType fits to the JSON value; throws type_error.303 otherwise

Exceptions

type_error.303 in case passed type ReferenceType is incompatible with the stored JSON value; see example below

Constant.

{The example shows several calls to get_ref().,get_ref}

Since: version 1.1.0

Definition at line 19744 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename ReferenceType , typename std::enable_if< std::is_reference< ReferenceType >::value &&std::is_const< typename std::remove_reference< ReferenceType >::type >::value, int >::type = 0>

ReferenceType nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::get_ref ( ) const

inline

get a reference value (implicit)

get a reference value (implicit) Implicit reference access to the internally stored JSON value. No copies are made.

Warning: Writing data to the referee of the result yields an undefined state.

Template Parameters

ReferenceType reference type; must be a reference to array_t, object_t, string_t, boolean_t, number_integer_t, or number_float_t. Enforced by static assertion.

Returns: reference to the internally stored JSON value if the requested reference type ReferenceType fits to the JSON value; throws type_error.303 otherwise

Exceptions

type_error.303 in case passed type ReferenceType is incompatible with the stored JSON value; see example below

Constant.

{The example shows several calls to get_ref().,get_ref}

Since: version 1.1.0

Definition at line 19757 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename ReferenceType , typename ThisType >

static ReferenceType nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::get_ref_impl ( ThisType & obj )

inlinestaticprivate

helper function to implement get_ref()

This function helps to implement get_ref() without code duplication for const and non-const overloads

Template Parameters

ThisType will be deduced as basic_json or const basic_json

Exceptions

type_error.303 if ReferenceType does not match underlying value type of the current JSON

Definition at line 19384 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename ValueType , detail::enable_if_t< !detail::is_basic_json< ValueType >::value &&detail::has_from_json< basic_json_t, ValueType >::value, int > = 0>

ValueType& nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::get_to ( ValueType & v ) const

inlinenoexcept

get a value (explicit)

Explicit type conversion between the JSON value and a compatible value. The value is filled into the input parameter by calling the json_serializer<ValueType> from_json() method.

The function is equivalent to executing

ValueType v;

JSONSerializer<ValueType>::from_json(*this, v);

This overloads is chosen if:

ValueType is not basic_json,
json_serializer<ValueType> has a from_json() method of the form void from_json(const basic_json&, ValueType&), and

Template Parameters

ValueType the input parameter type.

Returns: the input parameter, allowing chaining calls.

Exceptions

what	json_serializer<ValueType> `from_json()` method throws

{The example below shows several conversions from JSON values to other types. There a few things to note: (1) Floating-point numbers can be converted to integers\, (2) A JSON array can be converted to a standard std::vector<short>\, (3) A JSON object can be converted to C++ associative containers such as std::unordered_map<std::string\, json>.,get_to}

Since: version 3.3.0

Definition at line 19589 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename ValueType , detail::enable_if_t< detail::is_basic_json< ValueType >::value, int > = 0>

ValueType& nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::get_to ( ValueType & v ) const

inline

Definition at line 19602 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename T , std::size_t N, typename Array = T (&)[N], detail::enable_if_t< detail::has_from_json< basic_json_t, Array >::value, int > = 0>

Array nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::get_to ( T(&) v[N] ) const

inlinenoexcept

Definition at line 19613 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

iterator nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::insert	(	const_iterator	pos,
		const basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType > &	val
	)

inline

inserts element

Inserts element val before iterator pos.

Parameters

[in]	pos	iterator before which the content will be inserted; may be the end() iterator
[in]	val	element to insert

Returns: iterator pointing to the inserted val.

Exceptions

type_error.309	if called on JSON values other than arrays; example: `"cannot use insert() with string"`
invalid_iterator.202	if pos is not an iterator of *this; example: `"iterator does not fit current value"`

Constant plus linear in the distance between pos and end of the container.

{The example shows how insert() is used.,insert}

Since: version 1.0.0

Definition at line 22105 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

iterator nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::insert	(	const_iterator	pos,
		basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType > &&	val
	)

inline

inserts element

inserts element Inserts element val before iterator pos.

Parameters

[in]	pos	iterator before which the content will be inserted; may be the end() iterator
[in]	val	element to insert

Returns: iterator pointing to the inserted val.

Exceptions

type_error.309	if called on JSON values other than arrays; example: `"cannot use insert() with string"`
invalid_iterator.202	if pos is not an iterator of *this; example: `"iterator does not fit current value"`

Constant plus linear in the distance between pos and end of the container.

{The example shows how insert() is used.,insert}

Since: version 1.0.0

Definition at line 22127 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

iterator nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::insert	(	const_iterator	pos,
		size_type	cnt,
		const basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType > &	val
	)

inline

inserts elements

Inserts cnt copies of val before iterator pos.

Parameters

[in]	pos	iterator before which the content will be inserted; may be the end() iterator
[in]	cnt	number of copies of val to insert
[in]	val	element to insert

Returns: iterator pointing to the first element inserted, or pos if cnt==0

Exceptions

type_error.309	if called on JSON values other than arrays; example: `"cannot use insert() with string"`
invalid_iterator.202	if pos is not an iterator of *this; example: `"iterator does not fit current value"`

Linear in cnt plus linear in the distance between pos and end of the container.

{The example shows how insert() is used.,insert__count}

Since: version 1.0.0

Definition at line 22156 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

iterator nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::insert	(	const_iterator	pos,
		const_iterator	first,
		const_iterator	last
	)

inline

inserts elements

Inserts elements from range [first, last) before iterator pos.

Parameters

[in]	pos	iterator before which the content will be inserted; may be the end() iterator
[in]	first	begin of the range of elements to insert
[in]	last	end of the range of elements to insert

Exceptions

type_error.309	if called on JSON values other than arrays; example: `"cannot use insert() with string"`
invalid_iterator.202	if pos is not an iterator of *this; example: `"iterator does not fit current value"`
invalid_iterator.210	if first and last do not belong to the same JSON value; example: `"iterators do not fit"`
invalid_iterator.211	if first or last are iterators into container for which insert is called; example: `"passed iterators may not belong to container"`

Returns: iterator pointing to the first element inserted, or pos if first==last

Linear in std::distance(first, last) plus linear in the distance between pos and end of the container.

{The example shows how insert() is used.,insert__range}

Since: version 1.0.0

Definition at line 22204 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

iterator nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::insert	(	const_iterator	pos,
		initializer_list_t	ilist
	)

inline

inserts elements

Inserts elements from initializer list ilist before iterator pos.

Parameters

[in]	pos	iterator before which the content will be inserted; may be the end() iterator
[in]	ilist	initializer list to insert the values from

Exceptions

type_error.309	if called on JSON values other than arrays; example: `"cannot use insert() with string"`
invalid_iterator.202	if pos is not an iterator of *this; example: `"iterator does not fit current value"`

Returns: iterator pointing to the first element inserted, or pos if ilist is empty

Linear in ilist.size() plus linear in the distance between pos and end of the container.

{The example shows how insert() is used.,insert__ilist}

Since: version 1.0.0

Definition at line 22257 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::insert	(	const_iterator	first,
		const_iterator	last
	)

inline

inserts elements

Inserts elements from range [first, last).

Parameters

[in]	first	begin of the range of elements to insert
[in]	last	end of the range of elements to insert

Exceptions

type_error.309	if called on JSON values other than objects; example: `"cannot use insert() with string"`
invalid_iterator.202	if iterator first or last does does not point to an object; example: `"iterators first and last must point to objects"`
invalid_iterator.210	if first and last do not belong to the same JSON value; example: `"iterators do not fit"`

Logarithmic: O(N*log(size() + N)), where N is the number of elements to insert.

{The example shows how insert() is used.,insert__range_object}

Since: version 3.0.0

Definition at line 22298 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename... Args>

iterator nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::insert_iterator	(	const_iterator	pos,
		Args &&...	args
	)

inline

Helper for insertion of an iterator

Note: : This uses std::distance to support GCC 4.8, see https://github.com/nlohmann/json/pull/1257

Definition at line 22067 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

constexpr bool nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::is_array ( ) const

inlinenoexcept

return whether value is an array

This function returns true if and only if the JSON value is an array.

Returns: true if type is array, false otherwise.

Constant.

No-throw guarantee: this member function never throws exceptions.

{The following code exemplifies is_array() for all JSON types.,is_array}

Since: version 1.0.0

Definition at line 19156 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

constexpr bool nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::is_binary ( ) const

inlinenoexcept

return whether value is a binary array

This function returns true if and only if the JSON value is a binary array.

Returns: true if type is binary array, false otherwise.

Constant.

No-throw guarantee: this member function never throws exceptions.

{The following code exemplifies is_binary() for all JSON types.,is_binary}

Since: version 3.8.0

Definition at line 19200 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

constexpr bool nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::is_boolean ( ) const

inlinenoexcept

return whether value is a boolean

This function returns true if and only if the JSON value is a boolean.

Returns: true if type is boolean, false otherwise.

Constant.

No-throw guarantee: this member function never throws exceptions.

{The following code exemplifies is_boolean() for all JSON types.,is_boolean}

Since: version 1.0.0

Definition at line 18997 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

constexpr bool nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::is_discarded ( ) const

inlinenoexcept

return whether value is discarded

This function returns true if and only if the JSON value was discarded during parsing with a callback function (see parser_callback_t).

Note: This function will always be false for JSON values after parsing. That is, discarded values can only occur during parsing, but will be removed when inside a structured value or replaced by null in other cases.

Returns: true if type is discarded, false otherwise.

Constant.

No-throw guarantee: this member function never throws exceptions.

{The following code exemplifies is_discarded() for all JSON types.,is_discarded}

Since: version 1.0.0

Definition at line 19227 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

constexpr bool nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::is_null ( ) const

inlinenoexcept

return whether value is null

This function returns true if and only if the JSON value is null.

Returns: true if type is null, false otherwise.

Constant.

No-throw guarantee: this member function never throws exceptions.

{The following code exemplifies is_null() for all JSON types.,is_null}

Since: version 1.0.0

Definition at line 18975 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

constexpr bool nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::is_number ( ) const

inlinenoexcept

return whether value is a number

This function returns true if and only if the JSON value is a number. This includes both integer (signed and unsigned) and floating-point values.

Returns: true if type is number (regardless whether integer, unsigned integer or floating-type), false otherwise.

Constant.

No-throw guarantee: this member function never throws exceptions.

{The following code exemplifies is_number() for all JSON types.,is_number}

See also: is_number_integer() – check if value is an integer or unsigned integer number; is_number_unsigned() – check if value is an unsigned integer number; is_number_float() – check if value is a floating-point number

Since: version 1.0.0

Definition at line 19027 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

constexpr bool nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::is_number_float ( ) const

inlinenoexcept

return whether value is a floating-point number

This function returns true if and only if the JSON value is a floating-point number. This excludes signed and unsigned integer values.

Returns: true if type is a floating-point number, false otherwise.

Constant.

No-throw guarantee: this member function never throws exceptions.

{The following code exemplifies is_number_float() for all JSON types.,is_number_float}

See also: is_number() – check if value is number; is_number_integer() – check if value is an integer number; is_number_unsigned() – check if value is an unsigned integer number

Since: version 1.0.0

Definition at line 19112 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

constexpr bool nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::is_number_integer ( ) const

inlinenoexcept

return whether value is an integer number

This function returns true if and only if the JSON value is a signed or unsigned integer number. This excludes floating-point values.

Returns: true if type is an integer or unsigned integer number, false otherwise.

Constant.

No-throw guarantee: this member function never throws exceptions.

{The following code exemplifies is_number_integer() for all JSON types.,is_number_integer}

See also: is_number() – check if value is a number; is_number_unsigned() – check if value is an unsigned integer number; is_number_float() – check if value is a floating-point number

Since: version 1.0.0

Definition at line 19056 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

constexpr bool nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::is_number_unsigned ( ) const

inlinenoexcept

return whether value is an unsigned integer number

This function returns true if and only if the JSON value is an unsigned integer number. This excludes floating-point and signed integer values.

Returns: true if type is an unsigned integer number, false otherwise.

Constant.

No-throw guarantee: this member function never throws exceptions.

{The following code exemplifies is_number_unsigned() for all JSON types.,is_number_unsigned}

See also: is_number() – check if value is a number; is_number_integer() – check if value is an integer or unsigned integer number; is_number_float() – check if value is a floating-point number

Since: version 2.0.0

Definition at line 19084 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

constexpr bool nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::is_object ( ) const

inlinenoexcept

return whether value is an object

This function returns true if and only if the JSON value is an object.

Returns: true if type is object, false otherwise.

Constant.

No-throw guarantee: this member function never throws exceptions.

{The following code exemplifies is_object() for all JSON types.,is_object}

Since: version 1.0.0

Definition at line 19134 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

constexpr bool nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::is_primitive ( ) const

inlinenoexcept

return whether type is primitive

This function returns true if and only if the JSON type is primitive (string, number, boolean, or null).

Returns: true if type is primitive (string, number, boolean, or null), false otherwise.

Constant.

No-throw guarantee: this member function never throws exceptions.

{The following code exemplifies is_primitive() for all JSON types.,is_primitive}

See also: is_structured() – returns whether JSON value is structured; is_null() – returns whether JSON value is null; is_string() – returns whether JSON value is a string; is_boolean() – returns whether JSON value is a boolean; is_number() – returns whether JSON value is a number; is_binary() – returns whether JSON value is a binary array

Since: version 1.0.0

Definition at line 18926 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

constexpr bool nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::is_string ( ) const

inlinenoexcept

return whether value is a string

This function returns true if and only if the JSON value is a string.

Returns: true if type is string, false otherwise.

Constant.

No-throw guarantee: this member function never throws exceptions.

{The following code exemplifies is_string() for all JSON types.,is_string}

Since: version 1.0.0

Definition at line 19178 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

constexpr bool nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::is_structured ( ) const

inlinenoexcept

return whether type is structured

This function returns true if and only if the JSON type is structured (array or object).

Returns: true if type is structured (array or object), false otherwise.

Constant.

No-throw guarantee: this member function never throws exceptions.

{The following code exemplifies is_structured() for all JSON types.,is_structured}

See also: is_primitive() – returns whether value is primitive; is_array() – returns whether value is an array; is_object() – returns whether value is an object

Since: version 1.0.0

Definition at line 18953 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

iteration_proxy<iterator> nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::items ( )

inlinenoexcept

helper to access iterator member functions in range-based for

This function allows to access iterator::key() and iterator::value() during range-based for loops. In these loops, a reference to the JSON values is returned, so there is no access to the underlying iterator.

For loop without items() function:

for (auto it = j_object.begin(); it != j_object.end(); ++it)
{
    std::cout << "key: " << it.key() << ", value:" << it.value() << '\n';
}

Range-based for loop without items() function:

for (auto it : j_object)
{
    // "it" is of type json::reference and has no key() member
    std::cout << "value: " << it << '\n';
}

Range-based for loop with items() function:

for (auto& el : j_object.items())
{
    std::cout << "key: " << el.key() << ", value:" << el.value() << '\n';
}

The items() function also allows to use structured bindings (C++17):

for (auto& [key, val] : j_object.items())
{
    std::cout << "key: " << key << ", value:" << val << '\n';
}

Note: When iterating over an array, key() will return the index of the element as string (see example). For primitive types (e.g., numbers), key() returns an empty string.

Warning: Using items() on temporary objects is dangerous. Make sure the object's lifetime exeeds the iteration. See https://github.com/nlohmann/json/issues/2040 for more information.

Returns: iteration proxy object wrapping ref with an interface to use in range-based for loops

{The following code shows how the function is used.,items}

Strong guarantee: if an exception is thrown, there are no changes in the JSON value.

Constant.

Since: version 3.1.0, structured bindings support since 3.5.0.

Definition at line 21439 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

iteration_proxy<const_iterator> nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::items ( ) const

inlinenoexcept

helper to access iterator member functions in range-based for

This function allows to access iterator::key() and iterator::value() during range-based for loops. In these loops, a reference to the JSON values is returned, so there is no access to the underlying iterator.

For loop without items() function:

for (auto it = j_object.begin(); it != j_object.end(); ++it)
{
    std::cout << "key: " << it.key() << ", value:" << it.value() << '\n';
}

Range-based for loop without items() function:

for (auto it : j_object)
{
    // "it" is of type json::reference and has no key() member
    std::cout << "value: " << it << '\n';
}

Range-based for loop with items() function:

for (auto& el : j_object.items())
{
    std::cout << "key: " << el.key() << ", value:" << el.value() << '\n';
}

The items() function also allows to use structured bindings (C++17):

for (auto& [key, val] : j_object.items())
{
    std::cout << "key: " << key << ", value:" << val << '\n';
}

Note: When iterating over an array, key() will return the index of the element as string (see example). For primitive types (e.g., numbers), key() returns an empty string.

Warning: Using items() on temporary objects is dangerous. Make sure the object's lifetime exeeds the iteration. See https://github.com/nlohmann/json/issues/2040 for more information.

Returns: iteration proxy object wrapping ref with an interface to use in range-based for loops

{The following code shows how the function is used.,items}

Strong guarantee: if an exception is thrown, there are no changes in the JSON value.

Constant.

Since: version 3.1.0, structured bindings support since 3.5.0.

Definition at line 21447 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

static iteration_proxy<iterator> nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::iterator_wrapper ( reference ref )

inlinestaticnoexcept

wrapper to access iterator member functions in range-based for

This function allows to access iterator::key() and iterator::value() during range-based for loops. In these loops, a reference to the JSON values is returned, so there is no access to the underlying iterator.

For loop without iterator_wrapper:

for (auto it = j_object.begin(); it != j_object.end(); ++it)
{
    std::cout << "key: " << it.key() << ", value:" << it.value() << '\n';
}

Range-based for loop without iterator proxy:

for (auto it : j_object)
{
    // "it" is of type json::reference and has no key() member
    std::cout << "value: " << it << '\n';
}

Range-based for loop with iterator proxy:

for (auto it : json::iterator_wrapper(j_object))
{
    std::cout << "key: " << it.key() << ", value:" << it.value() << '\n';
}

Note: When iterating over an array, key() will return the index of the element as string (see example).

Parameters

[in] ref reference to a JSON value

Returns: iteration proxy object wrapping ref with an interface to use in range-based for loops

{The following code shows how the wrapper is used,iterator_wrapper}

Strong guarantee: if an exception is thrown, there are no changes in the JSON value.

Constant.

Note: The name of this function is not yet final and may change in the future.

Deprecated:: This stream operator is deprecated and will be removed in future 4.0.0 of the library. Please use items() instead; that is, replace json::iterator_wrapper(j) with j.items().

Definition at line 21357 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

static iteration_proxy<const_iterator> nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::iterator_wrapper ( const_reference ref )

inlinestaticnoexcept

wrapper to access iterator member functions in range-based for

This function allows to access iterator::key() and iterator::value() during range-based for loops. In these loops, a reference to the JSON values is returned, so there is no access to the underlying iterator.

For loop without iterator_wrapper:

for (auto it = j_object.begin(); it != j_object.end(); ++it)
{
    std::cout << "key: " << it.key() << ", value:" << it.value() << '\n';
}

Range-based for loop without iterator proxy:

for (auto it : j_object)
{
    // "it" is of type json::reference and has no key() member
    std::cout << "value: " << it << '\n';
}

Range-based for loop with iterator proxy:

for (auto it : json::iterator_wrapper(j_object))
{
    std::cout << "key: " << it.key() << ", value:" << it.value() << '\n';
}

Note: When iterating over an array, key() will return the index of the element as string (see example).

Parameters

[in] ref reference to a JSON value

Returns: iteration proxy object wrapping ref with an interface to use in range-based for loops

{The following code shows how the wrapper is used,iterator_wrapper}

Strong guarantee: if an exception is thrown, there are no changes in the JSON value.

Constant.

Note: The name of this function is not yet final and may change in the future.

Deprecated:: This stream operator is deprecated and will be removed in future 4.0.0 of the library. Please use items() instead; that is, replace json::iterator_wrapper(j) with j.items().

Definition at line 21366 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::json_value ( )

privatedefault

default constructor (for null values)

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::json_value ( boolean_t v )

inlineprivatenoexcept

constructor for booleans

Definition at line 17554 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::json_value ( number_integer_t v )

inlineprivatenoexcept

constructor for numbers (integer)

Definition at line 17556 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::json_value ( number_unsigned_t v )

inlineprivatenoexcept

constructor for numbers (unsigned)

Definition at line 17558 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::json_value ( number_float_t v )

inlineprivatenoexcept

constructor for numbers (floating-point)

Definition at line 17560 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::json_value ( value_t t )

inlineprivate

constructor for empty values of a given type

Definition at line 17562 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::json_value ( const string_t & value )

inlineprivate

constructor for strings

Definition at line 17633 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::json_value ( string_t && value )

inlineprivate

constructor for rvalue strings

Definition at line 17639 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::json_value ( const object_t & value )

inlineprivate

constructor for objects

Definition at line 17645 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::json_value ( object_t && value )

inlineprivate

constructor for rvalue objects

Definition at line 17651 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::json_value ( const array_t & value )

inlineprivate

constructor for arrays

Definition at line 17657 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::json_value ( array_t && value )

inlineprivate

constructor for rvalue arrays

Definition at line 17663 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::json_value ( const typename binary_t::container_type & value )

inlineprivate

constructor for binary arrays

Definition at line 17669 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::json_value ( typename binary_t::container_type && value )

inlineprivate

constructor for rvalue binary arrays

Definition at line 17675 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::json_value ( const binary_t & value )

inlineprivate

constructor for binary arrays (internal type)

Definition at line 17681 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::json_value ( binary_t && value )

inlineprivate

constructor for rvalue binary arrays (internal type)

Definition at line 17687 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

size_type nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::max_size ( ) const

inlinenoexcept

returns the maximum possible number of elements

Returns the maximum number of elements a JSON value is able to hold due to system or library implementation limitations, i.e. std::distance(begin(), end()) for the JSON value.

Returns

The return value depends on the different types and is defined as follows:

Value type	return value
null	`0` (same as `size()`)
boolean	`1` (same as `size()`)
string	`1` (same as `size()`)
number	`1` (same as `size()`)
binary	`1` (same as `size()`)
object	result of function `object_t::max_size()`
array	result of function `array_t::max_size()`

{The following code calls max_size() on the different value types. Note the output is implementation specific.,max_size}

Constant, as long as array_t and object_t satisfy the Container concept; that is, their max_size() functions have constant complexity.

No changes.

No-throw guarantee: this function never throws exceptions.

This function helps basic_json satisfying the Container requirements:

The complexity is constant.
Has the semantics of returning b.size() where b is the largest possible JSON value.

See also: size() – returns the number of elements

Since: version 1.0.0

Definition at line 21648 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::merge_patch ( const basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType > & apply_patch )

inline

applies a JSON Merge Patch

The merge patch format is primarily intended for use with the HTTP PATCH method as a means of describing a set of modifications to a target resource's content. This function applies a merge patch to the current JSON value.

The function implements the following algorithm from Section 2 of RFC 7396 (JSON Merge Patch):

define MergePatch(Target, Patch):
  if Patch is an Object:
    if Target is not an Object:
      Target = {} // Ignore the contents and set it to an empty Object
    for each Name/Value pair in Patch:
      if Value is null:
        if Name exists in Target:
          remove the Name/Value pair from Target
      else:
        Target[Name] = MergePatch(Target[Name], Value)
    return Target
  else:
    return Patch

Thereby, Target is the current object; that is, the patch is applied to the current value.

Parameters

[in] apply_patch the patch to apply

Linear in the lengths of patch.

{The following code shows how a JSON Merge Patch is applied to a JSON document.,merge_patch}

See also: patch – apply a JSON patch; RFC 7396 (JSON Merge Patch)

Since: version 3.0.0

Definition at line 25216 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::meta ( )

inlinestatic

returns version information on the library

This function returns a JSON object with information about the library, including the version number and information on the platform and compiler.

Returns

JSON object holding version information

key	description
`compiler`	Information on the used compiler. It is an object with the following keys: `c++` (the used C++ standard), `family` (the compiler family; possible values are `clang`, `icc`, `gcc`, `ilecpp`, `msvc`, `pgcpp`, `sunpro`, and `unknown`), and `version` (the compiler version).
`copyright`	The copyright line for the library as string.
`name`	The name of the library as string.
`platform`	The used platform as string. Possible values are `win32`, `linux`, `apple`, `unix`, and `unknown`.
`url`	The URL of the project as string.
`version`	The version of the library. It is an object with the following keys: `major`, `minor`, and `patch` as defined by Semantic Versioning, and `string` (the version string).

{The following code shows an example output of the meta() function.,meta}

Strong guarantee: if an exception is thrown, there are no changes to any JSON value.

Constant.

Since: 2.1.0

Definition at line 16912 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::object ( initializer_list_t init = {} )

inlinestatic

explicitly create an object from an initializer list

Creates a JSON object value from a given initializer list. The initializer lists elements must be pairs, and their first elements must be strings. If the initializer list is empty, the empty object {} is created.

Note: This function is only added for symmetry reasons. In contrast to the related function array(initializer_list_t), there are no cases which can only be expressed by this function. That is, any initializer list init can also be passed to the initializer list constructor basic_json(initializer_list_t, bool, value_t).

Parameters

[in] init initializer list to create an object from (optional)

Returns: JSON object value

Exceptions

type_error.301 if init is not a list of pairs whose first elements are strings. In this case, no object can be created. When such a value is passed to basic_json(initializer_list_t, bool, value_t), an array would have been created from the passed initializer list init. See example below.

Linear in the size of init.

Strong guarantee: if an exception is thrown, there are no changes to any JSON value.

{The following code shows an example for the object function.,object}

See also: basic_json(initializer_list_t, bool, value_t) – create a JSON value from an initializer list; array(initializer_list_t) – create a JSON array value from an initializer list

Since: version 1.0.0

Definition at line 18397 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

constexpr nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::operator value_t ( ) const

inlinenoexcept

return the type of the JSON value (implicit)

Implicitly return the type of the JSON value as a value from the value_t enumeration.

Returns: the type of the JSON value

Constant.

No-throw guarantee: this member function never throws exceptions.

{The following code exemplifies the value_t operator for all JSON types.,operator__value_t}

See also: type() – return the type of the JSON value (explicit); type_name() – return the type as string

Since: version 1.0.0

Definition at line 19253 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename ValueType , typename std::enable_if< !std::is_pointer< ValueType >::value &&!std::is_same< ValueType, detail::json_ref< basic_json >>::value &&!std::is_same< ValueType, typename string_t::value_type >::value &&!detail::is_basic_json< ValueType >::value &&!std::is_same< ValueType, std::initializer_list< typename string_t::value_type >>::value &&detail::is_detected< detail::get_template_function, const basic_json_t &, ValueType >::value, int >::type = 0>

JSON_EXPLICIT nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::operator ValueType ( ) const

inline

get a value (implicit)

Implicit type conversion between the JSON value and a compatible value. The call is realized by calling get() const.

Template Parameters

ValueType non-pointer type compatible to the JSON value, for instance int for JSON integer numbers, bool for JSON booleans, or std::vector types for JSON arrays. The character type of string_t as well as an initializer list of this type is excluded to avoid ambiguities as these types implicitly convert to std::string.

Returns: copy of the JSON value, converted to type ValueType

Exceptions

type_error.302 in case passed type ValueType is incompatible to the JSON value type (e.g., the JSON value is of type boolean, but a string is requested); see example below

Linear in the size of the JSON value.

{The example below shows several conversions from JSON values to other types. There a few things to note: (1) Floating-point numbers can be converted to integers\, (2) A JSON array can be converted to a standard std::vector<short>\, (3) A JSON object can be converted to C++ associative containers such as std::unordered_map<std::string\, json>.,operator__ValueType}

Since: version 1.0.0

Definition at line 19803 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

reference nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::operator+= ( basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType > && val )

inline

add an object to an array

add an object to an array Appends the given element val to the end of the JSON value. If the function is called on a JSON null value, an empty array is created before appending val.

Parameters

[in] val the value to add to the JSON array

Exceptions

type_error.308 when called on a type other than JSON array or null; example: "cannot use push_back() with number"

Amortized constant.

{The example shows how push_back() and += can be used to add elements to a JSON array. Note how the null value was silently converted to a JSON array.,push_back}

Since: version 1.0.0

Definition at line 21821 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

reference nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::operator+= ( const basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType > & val )

inline

add an object to an array

add an object to an array Appends the given element val to the end of the JSON value. If the function is called on a JSON null value, an empty array is created before appending val.

Parameters

[in] val the value to add to the JSON array

Exceptions

type_error.308 when called on a type other than JSON array or null; example: "cannot use push_back() with number"

Amortized constant.

{The example shows how push_back() and += can be used to add elements to a JSON array. Note how the null value was silently converted to a JSON array.,push_back}

Since: version 1.0.0

Definition at line 21855 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

reference nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::operator+= ( const typename object_t::value_type & val )

inline

add an object to an object

add an object to an object Inserts the given element val to the JSON object. If the function is called on a JSON null value, an empty object is created before inserting val.

Parameters

[in] val the value to add to the JSON object

Exceptions

type_error.308 when called on a type other than JSON object or null; example: "cannot use push_back() with number"

Logarithmic in the size of the container, O(log(size())).

{The example shows how push_back() and += can be used to add elements to a JSON object. Note how the null value was silently converted to a JSON object.,push_back__object_t__value}

Since: version 1.0.0

Definition at line 21905 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

reference nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::operator+= ( initializer_list_t init )

inline

add an object to an object

add an object to an object This function allows to use push_back with an initializer list. In case

the current value is an object,
the initializer list init contains only two elements, and
the first element of init is a string,

init is converted into an object element and added using push_back(const typename object_t::value_type&). Otherwise, init is converted to a JSON value and added using push_back(basic_json&&).

Parameters

[in] init an initializer list

Linear in the size of the initializer list init.

Note: This function is required to resolve an ambiguous overload error, because pairs like {"key", "value"} can be both interpreted as object_t::value_type or std::initializer_list<basic_json>, see https://github.com/nlohmann/json/issues/235 for more information.

{The example shows how initializer lists are treated as objects when possible.,push_back__initializer_list}

Definition at line 21954 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

basic_json& nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::operator= ( basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType > other )

inlinenoexcept

copy assignment

Copy assignment operator. Copies a JSON value via the "copy and swap" strategy: It is expressed in terms of the copy constructor, destructor, and the swap() member function.

Parameters

[in] other value to copy from

Linear.

This function helps basic_json satisfying the Container requirements:

The complexity is linear.

{The code below shows and example for the copy assignment. It creates a copy of value a which is then swapped with b. Finally\, the copy of a (which is the null value after the swap) is destroyed.,basic_json__copyassignment}

Since: version 1.0.0

Definition at line 18745 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

reference nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::operator[] ( size_type idx )

inline

access specified array element

Returns a reference to the element at specified location idx.

Note: If idx is beyond the range of the array (i.e., idx >= size()), then the array is silently filled up with null values to make idx a valid reference to the last stored element.

Parameters

[in] idx index of the element to access

Returns: reference to the element at index idx

Exceptions

type_error.305 if the JSON value is not an array or null; in that cases, using the [] operator with an index makes no sense.

Constant if idx is in the range of the array. Otherwise linear in idx - size().

{The example below shows how array elements can be read and written using [] operator. Note the addition of null values.,operatorarray__size_type}

Since: version 1.0.0

Definition at line 20071 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

const_reference nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::operator[] ( size_type idx ) const

inline

access specified array element

Returns a const reference to the element at specified location idx.

Parameters

[in] idx index of the element to access

Returns: const reference to the element at index idx

Exceptions

type_error.305 if the JSON value is not an array; in that case, using the [] operator with an index makes no sense.

Constant.

{The example below shows how array elements can be read using the [] operator.,operatorarray__size_type_const}

Since: version 1.0.0

Definition at line 20117 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

reference nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::operator[] ( const typename object_t::key_type & key )

inline

access specified object element

Returns a reference to the element at with specified key key.

Note: If key is not found in the object, then it is silently added to the object and filled with a null value to make key a valid reference. In case the value was null before, it is converted to an object.

Parameters

[in] key key of the element to access

Returns: reference to the element at key key

Exceptions

type_error.305 if the JSON value is not an object or null; in that cases, using the [] operator with a key makes no sense.

Logarithmic in the size of the container.

{The example below shows how object elements can be read and written using the [] operator.,operatorarray__key_type}

See also: at(const typename object_t::key_type&) for access by reference with range checking; value() for access by value with a default value

Since: version 1.0.0

Definition at line 20155 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

const_reference nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::operator[] ( const typename object_t::key_type & key ) const

inline

read-only access specified object element

Returns a const reference to the element at with specified key key. No bounds checking is performed.

Warning: If the element with key key does not exist, the behavior is undefined.

Parameters

[in] key key of the element to access

Returns: const reference to the element at key key

Precondition: The element with key key must exist. This precondition is enforced with an assertion.

Exceptions

type_error.305 if the JSON value is not an object; in that case, using the [] operator with a key makes no sense.

Logarithmic in the size of the container.

{The example below shows how object elements can be read using the [] operator.,operatorarray__key_type_const}

See also: at(const typename object_t::key_type&) for access by reference with range checking; value() for access by value with a default value

Since: version 1.0.0

Definition at line 20204 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename T >

reference nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::operator[] ( T * key )

inline

access specified object element

Returns a reference to the element at with specified key key.

Note: If key is not found in the object, then it is silently added to the object and filled with a null value to make key a valid reference. In case the value was null before, it is converted to an object.

Parameters

[in] key key of the element to access

Returns: reference to the element at key key

Exceptions

type_error.305 if the JSON value is not an object or null; in that cases, using the [] operator with a key makes no sense.

Logarithmic in the size of the container.

{The example below shows how object elements can be read and written using the [] operator.,operatorarray__key_type}

See also: at(const typename object_t::key_type&) for access by reference with range checking; value() for access by value with a default value

Since: version 1.1.0

Definition at line 20245 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename T >

const_reference nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::operator[] ( T * key ) const

inline

read-only access specified object element

Returns a const reference to the element at with specified key key. No bounds checking is performed.

Warning: If the element with key key does not exist, the behavior is undefined.

Parameters

[in] key key of the element to access

Returns: const reference to the element at key key

Precondition: The element with key key must exist. This precondition is enforced with an assertion.

Exceptions

type_error.305 if the JSON value is not an object; in that case, using the [] operator with a key makes no sense.

Logarithmic in the size of the container.

{The example below shows how object elements can be read using the [] operator.,operatorarray__key_type_const}

See also: at(const typename object_t::key_type&) for access by reference with range checking; value() for access by value with a default value

Since: version 1.1.0

Definition at line 20296 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

reference nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::operator[] ( const json_pointer & ptr )

inline

access specified element via JSON Pointer

Uses a JSON pointer to retrieve a reference to the respective JSON value. No bound checking is performed. Similar to operator[](const typename object_t::key_type&), null values are created in arrays and objects if necessary.

In particular:

If the JSON pointer points to an object key that does not exist, it is created an filled with a null value before a reference to it is returned.
If the JSON pointer points to an array index that does not exist, it is created an filled with a null value before a reference to it is returned. All indices between the current maximum and the given index are also filled with null.
The special value - is treated as a synonym for the index past the end.

Parameters

[in] ptr a JSON pointer

Returns: reference to the element pointed to by ptr

Constant.

Exceptions

parse_error.106	if an array index begins with '0'
parse_error.109	if an array index was not a number
out_of_range.404	if the JSON pointer can not be resolved

{The behavior is shown in the example.,operatorjson_pointer}

Since: version 2.0.0

Definition at line 24506 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

const_reference nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::operator[] ( const json_pointer & ptr ) const

inline

access specified element via JSON Pointer

Uses a JSON pointer to retrieve a reference to the respective JSON value. No bound checking is performed. The function does not change the JSON value; no null values are created. In particular, the special value - yields an exception.

Parameters

[in] ptr JSON pointer to the desired element

Returns: const reference to the element pointed to by ptr

Constant.

Exceptions

parse_error.106	if an array index begins with '0'
parse_error.109	if an array index was not a number
out_of_range.402	if the array index '-' is used
out_of_range.404	if the JSON pointer can not be resolved

{The behavior is shown in the example.,operatorjson_pointer_const}

Since: version 2.0.0

Definition at line 24534 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename InputType >

static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::parse	(	InputType &&	i,
		const parser_callback_t	cb = `nullptr`,
		const bool	allow_exceptions = `true`,
		const bool	ignore_comments = `false`
	)

inlinestatic

deserialize from a compatible input

Template Parameters

InputType

A compatible input, for instance

an std::istream object
a FILE pointer
a C-style array of characters
a pointer to a null-terminated string of single byte characters
an object obj for which begin(obj) and end(obj) produces a valid pair of iterators.

Parameters

[in]	i	input to read from
[in]	cb	a parser callback function of type parser_callback_t which is used to control the deserialization by filtering unwanted values (optional)
[in]	allow_exceptions	whether to throw exceptions in case of a parse error (optional, true by default)
[in]	ignore_comments	whether comments should be ignored and treated like whitespace (true) or yield a parse error (true); (optional, false by default)

Returns: deserialized JSON value; in case of a parse error and allow_exceptions set to false, the return value will be value_t::discarded.

Exceptions

parse_error.101	if a parse error occurs; example: `""unexpected end of input; expected string literal""`
parse_error.102	if to_unicode fails or surrogate error
parse_error.103	if to_unicode fails

Linear in the length of the input. The parser is a predictive LL(1) parser. The complexity can be higher if the parser callback function cb or reading from the input i has a super-linear complexity.

Note: A UTF-8 byte order mark is silently ignored.

{The example below demonstrates the parse() function reading from an array.,parse__array__parser_callback_t}

{The example below demonstrates the parse() function with and without callback function.,parse__string__parser_callback_t}

{The example below demonstrates the parse() function with and without callback function.,parse__istream__parser_callback_t}

{The example below demonstrates the parse() function reading from a contiguous container.,parse__contiguouscontainer__parser_callback_t}

Since: version 2.0.3 (contiguous containers); version 3.9.0 allowed to ignore comments.

Definition at line 23219 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename IteratorType >

static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::parse	(	IteratorType	first,
		IteratorType	last,
		const parser_callback_t	cb = `nullptr`,
		const bool	allow_exceptions = `true`,
		const bool	ignore_comments = `false`
	)

inlinestatic

deserialize from a pair of character iterators

The value_type of the iterator must be a integral type with size of 1, 2 or 4 bytes, which will be interpreted respectively as UTF-8, UTF-16 and UTF-32.

Parameters

[in]	first	iterator to start of character range
[in]	last	iterator to end of character range
[in]	cb	a parser callback function of type parser_callback_t which is used to control the deserialization by filtering unwanted values (optional)
[in]	allow_exceptions	whether to throw exceptions in case of a parse error (optional, true by default)
[in]	ignore_comments	whether comments should be ignored and treated like whitespace (true) or yield a parse error (true); (optional, false by default)

Returns: deserialized JSON value; in case of a parse error and allow_exceptions set to false, the return value will be value_t::discarded.

Exceptions

parse_error.101	if a parse error occurs; example: `""unexpected end of input; expected string literal""`
parse_error.102	if to_unicode fails or surrogate error
parse_error.103	if to_unicode fails

Definition at line 23257 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::parse	(	detail::span_input_adapter &&	i,
		const parser_callback_t	cb = `nullptr`,
		const bool	allow_exceptions = `true`,
		const bool	ignore_comments = `false`
	)

inlinestatic

Definition at line 23270 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename InputAdapterType >

static ::nlohmann::detail::parser<basic_json, InputAdapterType> nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::parser	(	InputAdapterType	adapter,
		detail::parser_callback_t< basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType > >	cb = `nullptr`,
		const bool	allow_exceptions = `true`,
		const bool	ignore_comments = `false`
	)

inlineprivate

Definition at line 16763 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::patch ( const basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType > & json_patch ) const

inline

applies a JSON patch

JSON Patch defines a JSON document structure for expressing a sequence of operations to apply to a JSON) document. With this function, a JSON Patch is applied to the current JSON value by executing all operations from the patch.

Parameters

[in] json_patch JSON patch document

Returns: patched document

Note: The application of a patch is atomic: Either all operations succeed and the patched document is returned or an exception is thrown. In any case, the original value is not changed: the patch is applied to a copy of the value.

Exceptions

parse_error.104	if the JSON patch does not consist of an array of objects
parse_error.105	if the JSON patch is malformed (e.g., mandatory attributes are missing); example: `"operation add must have member path"`
out_of_range.401	if an array index is out of range.
out_of_range.403	if a JSON pointer inside the patch could not be resolved successfully in the current JSON value; example: `"key baz not found"`
out_of_range.405	if JSON pointer has no parent ("add", "remove", "move")
other_error.501	if "test" operation was unsuccessful

Linear in the size of the JSON value and the length of the JSON patch. As usually only a fraction of the JSON value is affected by the patch, the complexity can usually be neglected.

{The following code shows how a JSON patch is applied to a value.,patch}

See also: diff – create a JSON patch by comparing two JSON values; RFC 6902 (JSON Patch); RFC 6901 (JSON Pointer)

Since: version 2.0.0

Definition at line 24745 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::push_back ( basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType > && val )

inline

add an object to an array

Appends the given element val to the end of the JSON value. If the function is called on a JSON null value, an empty array is created before appending val.

Parameters

[in] val the value to add to the JSON array

Exceptions

type_error.308 when called on a type other than JSON array or null; example: "cannot use push_back() with number"

Amortized constant.

{The example shows how push_back() and += can be used to add elements to a JSON array. Note how the null value was silently converted to a JSON array.,push_back}

Since: version 1.0.0

Definition at line 21796 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::push_back ( const basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType > & val )

inline

add an object to an array

add an object to an array Appends the given element val to the end of the JSON value. If the function is called on a JSON null value, an empty array is created before appending val.

Parameters

[in] val the value to add to the JSON array

Exceptions

type_error.308 when called on a type other than JSON array or null; example: "cannot use push_back() with number"

Amortized constant.

{The example shows how push_back() and += can be used to add elements to a JSON array. Note how the null value was silently converted to a JSON array.,push_back}

Since: version 1.0.0

Definition at line 21831 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::push_back ( const typename object_t::value_type & val )

inline

add an object to an object

Inserts the given element val to the JSON object. If the function is called on a JSON null value, an empty object is created before inserting val.

Parameters

[in] val the value to add to the JSON object

Exceptions

type_error.308 when called on a type other than JSON object or null; example: "cannot use push_back() with number"

Logarithmic in the size of the container, O(log(size())).

{The example shows how push_back() and += can be used to add elements to a JSON object. Note how the null value was silently converted to a JSON object.,push_back__object_t__value}

Since: version 1.0.0

Definition at line 21881 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::push_back ( initializer_list_t init )

inline

add an object to an object

This function allows to use push_back with an initializer list. In case

the current value is an object,
the initializer list init contains only two elements, and
the first element of init is a string,

init is converted into an object element and added using push_back(const typename object_t::value_type&). Otherwise, init is converted to a JSON value and added using push_back(basic_json&&).

Parameters

[in] init an initializer list

Linear in the size of the initializer list init.

Note: This function is required to resolve an ambiguous overload error, because pairs like {"key", "value"} can be both interpreted as object_t::value_type or std::initializer_list<basic_json>, see https://github.com/nlohmann/json/issues/235 for more information.

{The example shows how initializer lists are treated as objects when possible.,push_back__initializer_list}

Definition at line 21936 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

reverse_iterator nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::rbegin ( )

inlinenoexcept

returns an iterator to the reverse-beginning

Returns an iterator to the reverse-beginning; that is, the last element.

Illustration from cppreference.com

Constant.

This function helps basic_json satisfying the ReversibleContainer requirements:

The complexity is constant.
Has the semantics of reverse_iterator(end()).

{The following code shows an example for rbegin().,rbegin}

See also: crbegin() – returns a const reverse iterator to the beginning; rend() – returns a reverse iterator to the end; crend() – returns a const reverse iterator to the end

Since: version 1.0.0

Definition at line 21190 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

const_reverse_iterator nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::rbegin ( ) const

inlinenoexcept

returns a const reverse iterator to the last element

Returns a const iterator to the reverse-beginning; that is, the last element.

Illustration from cppreference.com

Constant.

This function helps basic_json satisfying the ReversibleContainer requirements:

The complexity is constant.
Has the semantics of const_cast<const basic_json&>(*this).rbegin().

{The following code shows an example for crbegin().,crbegin}

See also: rbegin() – returns a reverse iterator to the beginning; rend() – returns a reverse iterator to the end; crend() – returns a const reverse iterator to the end

Since: version 1.0.0

Definition at line 21198 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

reverse_iterator nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::rend ( )

inlinenoexcept

returns an iterator to the reverse-end

Returns an iterator to the reverse-end; that is, one before the first element.

Illustration from cppreference.com

Constant.

This function helps basic_json satisfying the ReversibleContainer requirements:

The complexity is constant.
Has the semantics of reverse_iterator(begin()).

{The following code shows an example for rend().,rend}

See also: crend() – returns a const reverse iterator to the end; rbegin() – returns a reverse iterator to the beginning; crbegin() – returns a const reverse iterator to the beginning

Since: version 1.0.0

Definition at line 21227 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

const_reverse_iterator nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::rend ( ) const

inlinenoexcept

returns a const reverse iterator to one before the first

Returns a const reverse iterator to the reverse-end; that is, one before the first element.

Illustration from cppreference.com

Constant.

This function helps basic_json satisfying the ReversibleContainer requirements:

The complexity is constant.
Has the semantics of const_cast<const basic_json&>(*this).rend().

{The following code shows an example for crend().,crend}

See also: rend() – returns a reverse iterator to the end; rbegin() – returns a reverse iterator to the beginning; crbegin() – returns a const reverse iterator to the beginning

Since: version 1.0.0

Definition at line 21235 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename InputType , typename SAX >

static bool nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::sax_parse	(	InputType &&	i,
		SAX *	sax,
		input_format_t	format = `input_format_t::json`,
		const bool	strict = `true`,
		const bool	ignore_comments = `false`
	)

inlinestatic

generate SAX events

The SAX event lister must follow the interface of json_sax.

This function reads from a compatible input. Examples are:

an std::istream object
a FILE pointer
a C-style array of characters
a pointer to a null-terminated string of single byte characters
an object obj for which begin(obj) and end(obj) produces a valid pair of iterators.

Parameters

[in]	i	input to read from
[in,out]	sax	SAX event listener
[in]	format	the format to parse (JSON, CBOR, MessagePack, or UBJSON)
[in]	strict	whether the input has to be consumed completely
[in]	ignore_comments	whether comments should be ignored and treated like whitespace (true) or yield a parse error (true); (optional, false by default); only applies to the JSON file format.

Returns: return value of the last processed SAX event

Exceptions

parse_error.101	if a parse error occurs; example: `""unexpected end of input; expected string literal""`
parse_error.102	if to_unicode fails or surrogate error
parse_error.103	if to_unicode fails

Linear in the length of the input. The parser is a predictive LL(1) parser. The complexity can be higher if the SAX consumer sax has a super-linear complexity.

Note: A UTF-8 byte order mark is silently ignored.

{The example below demonstrates the sax_parse() function reading from string and processing the events with a user-defined SAX event consumer.,sax_parse}

Since: version 3.2.0

Definition at line 23374 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<class IteratorType , class SAX >

static bool nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::sax_parse	(	IteratorType	first,
		IteratorType	last,
		SAX *	sax,
		input_format_t	format = `input_format_t::json`,
		const bool	strict = `true`,
		const bool	ignore_comments = `false`
	)

inlinestatic

Definition at line 23387 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename SAX >

static bool nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::sax_parse	(	detail::span_input_adapter &&	i,
		SAX *	sax,
		input_format_t	format = `input_format_t::json`,
		const bool	strict = `true`,
		const bool	ignore_comments = `false`
	)

inlinestatic

Definition at line 23401 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

size_type nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::size ( ) const

inlinenoexcept

returns the number of elements

Returns the number of elements in a JSON value.

Returns

The return value depends on the different types and is defined as follows:

Value type	return value
null	`0`
boolean	`1`
string	`1`
number	`1`
binary	`1`
object	result of function object_t::size()
array	result of function array_t::size()

{The following code calls size() on the different value types.,size}

Constant, as long as array_t and object_t satisfy the Container concept; that is, their size() functions have constant complexity.

No changes.

No-throw guarantee: this function never throws exceptions.

Note: This function does not return the length of a string stored as JSON value - it returns the number of elements in the JSON value which is 1 in the case of a string.

This function helps basic_json satisfying the Container requirements:

The complexity is constant.
Has the semantics of std::distance(begin(), end()).

See also: empty() – checks whether the container is empty; max_size() – returns the maximal number of elements

Since: version 1.0.0

Definition at line 21577 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::swap ( reference other )

inlinenoexcept

exchanges the values

Exchanges the contents of the JSON value with those of other. Does not invoke any move, copy, or swap operations on individual elements. All iterators and references remain valid. The past-the-end iterator is invalidated.

Parameters

[in,out] other JSON value to exchange the contents with

Constant.

{The example below shows how JSON values can be swapped with swap().,swap__reference}

Since: version 1.0.0

Definition at line 22442 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::swap ( array_t & other )

inline

exchanges the values

Exchanges the contents of a JSON array with those of other. Does not invoke any move, copy, or swap operations on individual elements. All iterators and references remain valid. The past-the-end iterator is invalidated.

Parameters

[in,out] other array to exchange the contents with

Exceptions

type_error.310 when JSON value is not an array; example: "cannot use swap() with string"

Constant.

{The example below shows how arrays can be swapped with swap().,swap__array_t}

Since: version 1.0.0

Definition at line 22502 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::swap ( object_t & other )

inline

exchanges the values

Exchanges the contents of a JSON object with those of other. Does not invoke any move, copy, or swap operations on individual elements. All iterators and references remain valid. The past-the-end iterator is invalidated.

Parameters

[in,out] other object to exchange the contents with

Exceptions

type_error.310 when JSON value is not an object; example: "cannot use swap() with string"

Constant.

{The example below shows how objects can be swapped with swap().,swap__object_t}

Since: version 1.0.0

Definition at line 22535 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::swap ( string_t & other )

inline

exchanges the values

Exchanges the contents of a JSON string with those of other. Does not invoke any move, copy, or swap operations on individual elements. All iterators and references remain valid. The past-the-end iterator is invalidated.

Parameters

[in,out] other string to exchange the contents with

Exceptions

type_error.310 when JSON value is not a string; example: "cannot use swap() with boolean"

Constant.

{The example below shows how strings can be swapped with swap().,swap__string_t}

Since: version 1.0.0

Definition at line 22568 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::swap ( binary_t & other )

inline

exchanges the values

Exchanges the contents of a JSON string with those of other. Does not invoke any move, copy, or swap operations on individual elements. All iterators and references remain valid. The past-the-end iterator is invalidated.

Parameters

[in,out] other binary to exchange the contents with

Exceptions

type_error.310 when JSON value is not a string; example: "cannot use swap() with boolean"

Constant.

{The example below shows how strings can be swapped with swap().,swap__binary_t}

Since: version 3.8.0

Definition at line 22601 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::swap ( typename binary_t::container_type & other )

inline

Definition at line 22615 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

static std::vector<uint8_t> nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::to_bson ( const basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType > & j )

inlinestatic

Serializes the given JSON object j to BSON and returns a vector containing the corresponding BSON-representation.

BSON (Binary JSON) is a binary format in which zero or more ordered key/value pairs are stored as a single entity (a so-called document).

The library uses the following mapping from JSON values types to BSON types:

JSON value type	value/range	BSON type	marker
null	`null`	null	0x0A
boolean	`true`, `false`	boolean	0x08
number_integer	-9223372036854775808..-2147483649	int64	0x12
number_integer	-2147483648..2147483647	int32	0x10
number_integer	2147483648..9223372036854775807	int64	0x12
number_unsigned	0..2147483647	int32	0x10
number_unsigned	2147483648..9223372036854775807	int64	0x12
number_unsigned	9223372036854775808..18446744073709551615	–	–
number_float	any value	double	0x01
string	any value	string	0x02
array	any value	document	0x04
object	any value	document	0x03
binary	any value	binary	0x05

Warning: The mapping is incomplete, since only JSON-objects (and things contained therein) can be serialized to BSON. Also, integers larger than 9223372036854775807 cannot be serialized to BSON, and the keys may not contain U+0000, since they are serialized a zero-terminated c-strings.

Exceptions

out_of_range.407	if `j.is_number_unsigned() && j.get<std::uint64_t>() > 9223372036854775807`
out_of_range.409	if a key in `j` contains a NULL (U+0000)
type_error.317	if `!j.is_object()`

Precondition: The input j is required to be an object: j.is_object() == true.

Note: Any BSON output created via to_bson can be successfully parsed by from_bson.

Parameters

[in] j JSON value to serialize

Returns: BSON serialization as byte vector

Linear in the size of the JSON value j.

{The example shows the serialization of a JSON value to a byte vector in BSON format.,to_bson}

See also: http://bsonspec.org/spec.html; from_bson(detail::input_adapter&&, const bool strict) for the analogous deserialization; to_ubjson(const basic_json&, const bool, const bool) for the related UBJSON format; to_cbor(const basic_json&) for the related CBOR format; to_msgpack(const basic_json&) for the related MessagePack format

Definition at line 23910 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

static void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::to_bson	(	const basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType > &	j,
		detail::output_adapter< uint8_t >	o
	)

inlinestatic

Serializes the given JSON object j to BSON and forwards the corresponding BSON-representation to the given output_adapter o.

Parameters

j	The JSON object to convert to BSON.
o	The output adapter that receives the binary BSON representation.

Precondition: The input j shall be an object: j.is_object() == true

See also: to_bson(const basic_json&)

Definition at line 23925 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

static void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::to_bson	(	const basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType > &	j,
		detail::output_adapter< char >	o
	)

inlinestatic

Serializes the given JSON object j to BSON and forwards the corresponding BSON-representation to the given output_adapter o.

Parameters

j	The JSON object to convert to BSON.
o	The output adapter that receives the binary BSON representation.

Precondition: The input j shall be an object: j.is_object() == true

See also: to_bson(const basic_json&)

Definition at line 23933 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

static std::vector<uint8_t> nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::to_cbor ( const basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType > & j )

inlinestatic

create a CBOR serialization of a given JSON value

Serializes a given JSON value j to a byte vector using the CBOR (Concise Binary Object Representation) serialization format. CBOR is a binary serialization format which aims to be more compact than JSON itself, yet more efficient to parse.

The library uses the following mapping from JSON values types to CBOR types according to the CBOR specification (RFC 7049):

JSON value type	value/range	CBOR type	first byte
null	`null`	Null	0xF6
boolean	`true`	True	0xF5
boolean	`false`	False	0xF4
number_integer	-9223372036854775808..-2147483649	Negative integer (8 bytes follow)	0x3B
number_integer	-2147483648..-32769	Negative integer (4 bytes follow)	0x3A
number_integer	-32768..-129	Negative integer (2 bytes follow)	0x39
number_integer	-128..-25	Negative integer (1 byte follow)	0x38
number_integer	-24..-1	Negative integer	0x20..0x37
number_integer	0..23	Integer	0x00..0x17
number_integer	24..255	Unsigned integer (1 byte follow)	0x18
number_integer	256..65535	Unsigned integer (2 bytes follow)	0x19
number_integer	65536..4294967295	Unsigned integer (4 bytes follow)	0x1A
number_integer	4294967296..18446744073709551615	Unsigned integer (8 bytes follow)	0x1B
number_unsigned	0..23	Integer	0x00..0x17
number_unsigned	24..255	Unsigned integer (1 byte follow)	0x18
number_unsigned	256..65535	Unsigned integer (2 bytes follow)	0x19
number_unsigned	65536..4294967295	Unsigned integer (4 bytes follow)	0x1A
number_unsigned	4294967296..18446744073709551615	Unsigned integer (8 bytes follow)	0x1B
number_float	any value representable by a float	Single-Precision Float	0xFA
number_float	any value NOT representable by a float	Double-Precision Float	0xFB
string	length: 0..23	UTF-8 string	0x60..0x77
string	length: 23..255	UTF-8 string (1 byte follow)	0x78
string	length: 256..65535	UTF-8 string (2 bytes follow)	0x79
string	length: 65536..4294967295	UTF-8 string (4 bytes follow)	0x7A
string	length: 4294967296..18446744073709551615	UTF-8 string (8 bytes follow)	0x7B
array	size: 0..23	array	0x80..0x97
array	size: 23..255	array (1 byte follow)	0x98
array	size: 256..65535	array (2 bytes follow)	0x99
array	size: 65536..4294967295	array (4 bytes follow)	0x9A
array	size: 4294967296..18446744073709551615	array (8 bytes follow)	0x9B
object	size: 0..23	map	0xA0..0xB7
object	size: 23..255	map (1 byte follow)	0xB8
object	size: 256..65535	map (2 bytes follow)	0xB9
object	size: 65536..4294967295	map (4 bytes follow)	0xBA
object	size: 4294967296..18446744073709551615	map (8 bytes follow)	0xBB
binary	size: 0..23	byte string	0x40..0x57
binary	size: 23..255	byte string (1 byte follow)	0x58
binary	size: 256..65535	byte string (2 bytes follow)	0x59
binary	size: 65536..4294967295	byte string (4 bytes follow)	0x5A
binary	size: 4294967296..18446744073709551615	byte string (8 bytes follow)	0x5B

Note

The mapping is complete in the sense that any JSON value type can be converted to a CBOR value.

If NaN or Infinity are stored inside a JSON number, they are serialized properly. This behavior differs from the dump() function which serializes NaN or Infinity to null.

The following CBOR types are not used in the conversion:

UTF-8 strings terminated by "break" (0x7F)
arrays terminated by "break" (0x9F)
maps terminated by "break" (0xBF)
byte strings terminated by "break" (0x5F)
date/time (0xC0..0xC1)
bignum (0xC2..0xC3)
decimal fraction (0xC4)
bigfloat (0xC5)
expected conversions (0xD5..0xD7)
simple values (0xE0..0xF3, 0xF8)
undefined (0xF7)
half-precision floats (0xF9)
break (0xFF)

Parameters

[in] j JSON value to serialize

Returns: CBOR serialization as byte vector

Linear in the size of the JSON value j.

{The example shows the serialization of a JSON value to a byte vector in CBOR format.,to_cbor}

See also: http://cbor.io; from_cbor(detail::input_adapter&&, const bool, const bool, const cbor_tag_handler_t) for the analogous deserialization; to_msgpack(const basic_json&) for the related MessagePack format; to_ubjson(const basic_json&, const bool, const bool) for the related UBJSON format

Since: version 2.0.9; compact representation of floating-point numbers since version 3.8.0

Definition at line 23634 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

static void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::to_cbor	(	const basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType > &	j,
		detail::output_adapter< uint8_t >	o
	)

inlinestatic

Definition at line 23641 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

static void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::to_cbor	(	const basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType > &	j,
		detail::output_adapter< char >	o
	)

inlinestatic

Definition at line 23646 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

static std::vector<uint8_t> nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::to_msgpack ( const basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType > & j )

inlinestatic

create a MessagePack serialization of a given JSON value

Serializes a given JSON value j to a byte vector using the MessagePack serialization format. MessagePack is a binary serialization format which aims to be more compact than JSON itself, yet more efficient to parse.

The library uses the following mapping from JSON values types to MessagePack types according to the MessagePack specification:

JSON value type	value/range	MessagePack type	first byte
null	`null`	nil	0xC0
boolean	`true`	true	0xC3
boolean	`false`	false	0xC2
number_integer	-9223372036854775808..-2147483649	int64	0xD3
number_integer	-2147483648..-32769	int32	0xD2
number_integer	-32768..-129	int16	0xD1
number_integer	-128..-33	int8	0xD0
number_integer	-32..-1	negative fixint	0xE0..0xFF
number_integer	0..127	positive fixint	0x00..0x7F
number_integer	128..255	uint 8	0xCC
number_integer	256..65535	uint 16	0xCD
number_integer	65536..4294967295	uint 32	0xCE
number_integer	4294967296..18446744073709551615	uint 64	0xCF
number_unsigned	0..127	positive fixint	0x00..0x7F
number_unsigned	128..255	uint 8	0xCC
number_unsigned	256..65535	uint 16	0xCD
number_unsigned	65536..4294967295	uint 32	0xCE
number_unsigned	4294967296..18446744073709551615	uint 64	0xCF
number_float	any value representable by a float	float 32	0xCA
number_float	any value NOT representable by a float	float 64	0xCB
string	length: 0..31	fixstr	0xA0..0xBF
string	length: 32..255	str 8	0xD9
string	length: 256..65535	str 16	0xDA
string	length: 65536..4294967295	str 32	0xDB
array	size: 0..15	fixarray	0x90..0x9F
array	size: 16..65535	array 16	0xDC
array	size: 65536..4294967295	array 32	0xDD
object	size: 0..15	fix map	0x80..0x8F
object	size: 16..65535	map 16	0xDE
object	size: 65536..4294967295	map 32	0xDF
binary	size: 0..255	bin 8	0xC4
binary	size: 256..65535	bin 16	0xC5
binary	size: 65536..4294967295	bin 32	0xC6

Note

The mapping is complete in the sense that any JSON value type can be converted to a MessagePack value.

The following values can not be converted to a MessagePack value:

strings with more than 4294967295 bytes
byte strings with more than 4294967295 bytes
arrays with more than 4294967295 elements
objects with more than 4294967295 elements

Any MessagePack output created to_msgpack can be successfully parsed by from_msgpack.

If NaN or Infinity are stored inside a JSON number, they are serialized properly. This behavior differs from the dump() function which serializes NaN or Infinity to null.

Parameters

[in] j JSON value to serialize

Returns: MessagePack serialization as byte vector

Linear in the size of the JSON value j.

{The example shows the serialization of a JSON value to a byte vector in MessagePack format.,to_msgpack}

See also: http://msgpack.org; from_msgpack for the analogous deserialization; to_cbor(const basic_json& for the related CBOR format; to_ubjson(const basic_json&, const bool, const bool) for the related UBJSON format

Since: version 2.0.9

Definition at line 23729 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

static void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::to_msgpack	(	const basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType > &	j,
		detail::output_adapter< uint8_t >	o
	)

inlinestatic

Definition at line 23736 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

static void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::to_msgpack	(	const basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType > &	j,
		detail::output_adapter< char >	o
	)

inlinestatic

Definition at line 23741 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

static std::vector<uint8_t> nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::to_ubjson	(	const basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType > &	j,
		const bool	use_size = `false`,
		const bool	use_type = `false`
	)

inlinestatic

create a UBJSON serialization of a given JSON value

Serializes a given JSON value j to a byte vector using the UBJSON (Universal Binary JSON) serialization format. UBJSON aims to be more compact than JSON itself, yet more efficient to parse.

The library uses the following mapping from JSON values types to UBJSON types according to the UBJSON specification:

JSON value type	value/range	UBJSON type	marker
null	`null`	null	`Z`
boolean	`true`	true	`T`
boolean	`false`	false	`F`
number_integer	-9223372036854775808..-2147483649	int64	`L`
number_integer	-2147483648..-32769	int32	`l`
number_integer	-32768..-129	int16	`I`
number_integer	-128..127	int8	`i`
number_integer	128..255	uint8	`U`
number_integer	256..32767	int16	`I`
number_integer	32768..2147483647	int32	`l`
number_integer	2147483648..9223372036854775807	int64	`L`
number_unsigned	0..127	int8	`i`
number_unsigned	128..255	uint8	`U`
number_unsigned	256..32767	int16	`I`
number_unsigned	32768..2147483647	int32	`l`
number_unsigned	2147483648..9223372036854775807	int64	`L`
number_unsigned	2147483649..18446744073709551615	high-precision	`H`
number_float	any value	float64	`D`
string	with shortest length indicator	string	`S`
array	see notes on optimized format	array	`[`
object	see notes on optimized format	map	`{`

Note

The mapping is complete in the sense that any JSON value type can be converted to a UBJSON value.

The following values can not be converted to a UBJSON value:

strings with more than 9223372036854775807 bytes (theoretical)

The following markers are not used in the conversion:

Z: no-op values are not created.
C: single-byte strings are serialized with S markers.

Any UBJSON output created to_ubjson can be successfully parsed by from_ubjson.

If NaN or Infinity are stored inside a JSON number, they are serialized properly. This behavior differs from the dump() function which serializes NaN or Infinity to null.

The optimized formats for containers are supported: Parameter use_size adds size information to the beginning of a container and removes the closing marker. Parameter use_type further checks whether all elements of a container have the same type and adds the type marker to the beginning of the container. The use_type parameter must only be used together with use_size = true. Note that use_size = true alone may result in larger representations - the benefit of this parameter is that the receiving side is immediately informed on the number of elements of the container.

If the JSON data contains the binary type, the value stored is a list of integers, as suggested by the UBJSON documentation. In particular, this means that serialization and the deserialization of a JSON containing binary values into UBJSON and back will result in a different JSON object.

Parameters

[in]	j	JSON value to serialize
[in]	use_size	whether to add size annotations to container types
[in]	use_type	whether to add type annotations to container types (must be combined with use_size = true)

Returns: UBJSON serialization as byte vector

Linear in the size of the JSON value j.

{The example shows the serialization of a JSON value to a byte vector in UBJSON format.,to_ubjson}

See also: http://ubjson.org; from_ubjson(detail::input_adapter&&, const bool, const bool) for the analogous deserialization; to_cbor(const basic_json& for the related CBOR format; to_msgpack(const basic_json&) for the related MessagePack format

Since: version 3.1.0

Definition at line 23832 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

static void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::to_ubjson	(	const basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType > &	j,
		detail::output_adapter< uint8_t >	o,
		const bool	use_size = `false`,
		const bool	use_type = `false`
	)

inlinestatic

Definition at line 23841 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

static void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::to_ubjson	(	const basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType > &	j,
		detail::output_adapter< char >	o,
		const bool	use_size = `false`,
		const bool	use_type = `false`
	)

inlinestatic

Definition at line 23847 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

constexpr value_t nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::type ( ) const

inlinenoexcept

return the type of the JSON value (explicit)

Return the type of the JSON value as a value from the value_t enumeration.

Returns

the type of the JSON value

Value type	return value
null	value_t::null
boolean	value_t::boolean
string	value_t::string
number (integer)	value_t::number_integer
number (unsigned integer)	value_t::number_unsigned
number (floating-point)	value_t::number_float
object	value_t::object
array	value_t::array
binary	value_t::binary
discarded	value_t::discarded

Constant.

No-throw guarantee: this member function never throws exceptions.

{The following code exemplifies type() for all JSON types.,type}

See also: operator value_t() – return the type of the JSON value (implicit); type_name() – return the type as string

Since: version 1.0.0

Definition at line 18895 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

JSON_HEDLEY_RETURNS_NON_NULL const char* nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::type_name ( ) const

inlinenoexcept

return the type as string

Returns the type name as string to be used in error messages - usually to indicate that a function was called on a wrong JSON type.

Returns

a string representation of a the m_type member:

Value type	return value
null	`"null"`
boolean	`"boolean"`
string	`"string"`
number	`"number"` (for all number types)
object	`"object"`
array	`"array"`
binary	`"binary"`
discarded	`"discarded"`

No-throw guarantee: this function never throws exceptions.

Constant.

{The following code exemplifies type_name() for all JSON types.,type_name}

See also: type() – return the type of the JSON value; operator value_t() – return the type of the JSON value (implicit)

Since: version 1.0.0, public since 2.1.0, const char* and noexcept since 3.0.0

Definition at line 23495 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::unflatten ( ) const

inline

unflatten a previously flattened JSON value

The function restores the arbitrary nesting of a JSON value that has been flattened before using the flatten() function. The JSON value must meet certain constraints:

The value must be an object.
The keys must be JSON pointers (see RFC 6901)
The mapped values must be primitive JSON types.

Returns: the original JSON from a flattened version

Note: Empty objects and arrays are flattened by flatten() to null values and can not unflattened to their original type. Apart from this example, for a JSON value j, the following is always true: j == j.flatten().unflatten().

Linear in the size the JSON value.

Exceptions

type_error.314	if value is not an object
type_error.315	if object values are not primitive

{The following code shows how a flattened JSON object is unflattened into the original nested JSON object.,unflatten}

See also: flatten() for the reverse function

Since: version 2.0.0

Definition at line 24684 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::update ( const_reference j )

inline

updates a JSON object from another object, overwriting existing keys

Inserts all values from JSON object j and overwrites existing keys.

Parameters

[in] j JSON object to read values from

Exceptions

type_error.312 if called on JSON values other than objects; example: "cannot use update() with string"

O(N*log(size() + N)), where N is the number of elements to insert.

{The example shows how update() is used.,update}

See also: https://docs.python.org/3.6/library/stdtypes.html#dict.update

Since: version 3.0.0

Definition at line 22340 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::update	(	const_iterator	first,
		const_iterator	last
	)

inline

updates a JSON object from another object, overwriting existing keys

Inserts all values from from range [first, last) and overwrites existing keys.

Parameters

[in]	first	begin of the range of elements to insert
[in]	last	end of the range of elements to insert

Exceptions

type_error.312	if called on JSON values other than objects; example: `"cannot use update() with string"`
invalid_iterator.202	if iterator first or last does does not point to an object; example: `"iterators first and last must point to objects"`
invalid_iterator.210	if first and last do not belong to the same JSON value; example: `"iterators do not fit"`

O(N*log(size() + N)), where N is the number of elements to insert.

{The example shows how update() is used__range.,update}

See also: https://docs.python.org/3.6/library/stdtypes.html#dict.update

Since: version 3.0.0

Definition at line 22391 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<class ValueType , typename std::enable_if< detail::is_getable< basic_json_t, ValueType >::value &&!std::is_same< value_t, ValueType >::value, int >::type = 0>

ValueType nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::value	(	const typename object_t::key_type &	key,
		const ValueType &	default_value
	)		const

inline

access specified object element with default value

Returns either a copy of an object's element at the specified key key or a given default value if no element with key key exists.

The function is basically equivalent to executing

try {
    return at(key);
} catch(out_of_range) {
    return default_value;
}

Note: Unlike at(const typename object_t::key_type&), this function does not throw if the given key key was not found.; Unlike operator[](const typename object_t::key_type& key), this function does not implicitly add an element to the position defined by key. This function is furthermore also applicable to const objects.

Parameters

[in]	key	key of the element to access
[in]	default_value	the value to return if key is not found

Template Parameters

ValueType type compatible to JSON values, for instance int for JSON integer numbers, bool for JSON booleans, or std::vector types for JSON arrays. Note the type of the expected value at key and the default value default_value must be compatible.

Returns: copy of the element at key key or default_value if key is not found

Exceptions

type_error.302	if default_value does not match the type of the value at key
type_error.306	if the JSON value is not an object; in that case, using `value()` with a key makes no sense.

Logarithmic in the size of the container.

{The example below shows how object elements can be queried with a default value.,basic_json__value}

See also: at(const typename object_t::key_type&) for access by reference with range checking; operator[](const typename object_t::key_type&) for unchecked access by reference

Since: version 1.0.0

Definition at line 20362 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

string_t nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::value	(	const typename object_t::key_type &	key,
		const char *	default_value
	)		const

inline

overload for a default value of type const char*

access specified object element with default value Returns either a copy of an object's element at the specified key key or a given default value if no element with key key exists.

The function is basically equivalent to executing

try {
    return at(key);
} catch(out_of_range) {
    return default_value;
}

Note: Unlike at(const typename object_t::key_type&), this function does not throw if the given key key was not found.; Unlike operator[](const typename object_t::key_type& key), this function does not implicitly add an element to the position defined by key. This function is furthermore also applicable to const objects.

Parameters

[in]	key	key of the element to access
[in]	default_value	the value to return if key is not found

Template Parameters

ValueType type compatible to JSON values, for instance int for JSON integer numbers, bool for JSON booleans, or std::vector types for JSON arrays. Note the type of the expected value at key and the default value default_value must be compatible.

Returns: copy of the element at key key or default_value if key is not found

Exceptions

type_error.302	if default_value does not match the type of the value at key
type_error.306	if the JSON value is not an object; in that case, using `value()` with a key makes no sense.

Logarithmic in the size of the container.

{The example below shows how object elements can be queried with a default value.,basic_json__value}

See also: at(const typename object_t::key_type&) for access by reference with range checking; operator[](const typename object_t::key_type&) for unchecked access by reference

Since: version 1.0.0

Definition at line 20384 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<class ValueType , typename std::enable_if< detail::is_getable< basic_json_t, ValueType >::value, int >::type = 0>

ValueType nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::value	(	const json_pointer &	ptr,
		const ValueType &	default_value
	)		const

inline

access specified object element via JSON Pointer with default value

Returns either a copy of an object's element at the specified key key or a given default value if no element with key key exists.

The function is basically equivalent to executing

try {
    return at(ptr);
} catch(out_of_range) {
    return default_value;
}

Note: Unlike at(const json_pointer&), this function does not throw if the given key key was not found.

Parameters

[in]	ptr	a JSON pointer to the element to access
[in]	default_value	the value to return if ptr found no value

Template Parameters

ValueType type compatible to JSON values, for instance int for JSON integer numbers, bool for JSON booleans, or std::vector types for JSON arrays. Note the type of the expected value at key and the default value default_value must be compatible.

Returns: copy of the element at key key or default_value if key is not found

Exceptions

type_error.302	if default_value does not match the type of the value at ptr
type_error.306	if the JSON value is not an object; in that case, using `value()` with a key makes no sense.

Logarithmic in the size of the container.

{The example below shows how object elements can be queried with a default value.,basic_json__value_ptr}

See also: operator[](const json_pointer&) for unchecked access by reference

Since: version 2.0.2

Definition at line 20434 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

string_t nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::value	(	const json_pointer &	ptr,
		const char *	default_value
	)		const

inline

overload for a default value of type const char*

Definition at line 20458 of file json.hpp.

Friends And Related Function Documentation

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename BasicJsonType , typename InputType , typename SAX >

friend class ::nlohmann::detail::binary_reader

friend

Definition at line 16749 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename BasicJsonType , typename CharType >

friend class ::nlohmann::detail::binary_writer

friend

Definition at line 16747 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename BasicJsonType >

friend class ::nlohmann::detail::iter_impl

friend

Definition at line 16745 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename BasicJsonType >

friend class ::nlohmann::detail::json_sax_dom_callback_parser

friend

Definition at line 16753 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename BasicJsonType >

friend class ::nlohmann::detail::json_sax_dom_parser

friend

Definition at line 16751 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename BasicJsonType , typename InputType >

friend class ::nlohmann::detail::parser

friend

Definition at line 16742 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<detail::value_t >

friend struct detail::external_constructor

friend

Definition at line 16738 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

bool operator!=	(	const_reference	lhs,
		const_reference	rhs
	)

friend

comparison: not equal

Compares two JSON values for inequality by calculating not (lhs == rhs).

Parameters

[in]	lhs	first JSON value to consider
[in]	rhs	second JSON value to consider

Returns: whether the values lhs and rhs are not equal

Linear.

No-throw guarantee: this function never throws exceptions.

{The example demonstrates comparing several JSON types.,operator__notequal}

Since: version 1.0.0

Definition at line 22801 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>

bool operator!=	(	const_reference	lhs,
		const ScalarType	rhs
	)

friend

comparison: not equal

comparison: not equal Compares two JSON values for inequality by calculating not (lhs == rhs).

Parameters

[in]	lhs	first JSON value to consider
[in]	rhs	second JSON value to consider

Returns: whether the values lhs and rhs are not equal

Linear.

No-throw guarantee: this function never throws exceptions.

{The example demonstrates comparing several JSON types.,operator__notequal}

Since: version 1.0.0

Definition at line 22812 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>

bool operator!=	(	const ScalarType	lhs,
		const_reference	rhs
	)

friend

comparison: not equal

comparison: not equal Compares two JSON values for inequality by calculating not (lhs == rhs).

Parameters

[in]	lhs	first JSON value to consider
[in]	rhs	second JSON value to consider

Returns: whether the values lhs and rhs are not equal

Linear.

No-throw guarantee: this function never throws exceptions.

{The example demonstrates comparing several JSON types.,operator__notequal}

Since: version 1.0.0

Definition at line 22823 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

bool operator<	(	const_reference	lhs,
		const_reference	rhs
	)

friend

comparison: less than

Compares whether one JSON value lhs is less than another JSON value rhs according to the following rules:

If lhs and rhs have the same type, the values are compared using the default < operator.
Integer and floating-point numbers are automatically converted before comparison
In case lhs and rhs have different types, the values are ignored and the order of the types is considered, see operator<(const value_t, const value_t).

Parameters

[in]	lhs	first JSON value to consider
[in]	rhs	second JSON value to consider

Returns: whether lhs is less than rhs

Linear.

No-throw guarantee: this function never throws exceptions.

{The example demonstrates comparing several JSON types.,operator__less}

Since: version 1.0.0

Definition at line 22854 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>

bool operator<	(	const_reference	lhs,
		const ScalarType	rhs
	)

friend

comparison: less than

comparison: less than Compares whether one JSON value lhs is less than another JSON value rhs according to the following rules:

If lhs and rhs have the same type, the values are compared using the default < operator.
Integer and floating-point numbers are automatically converted before comparison
In case lhs and rhs have different types, the values are ignored and the order of the types is considered, see operator<(const value_t, const value_t).

Parameters

[in]	lhs	first JSON value to consider
[in]	rhs	second JSON value to consider

Returns: whether lhs is less than rhs

Linear.

No-throw guarantee: this function never throws exceptions.

{The example demonstrates comparing several JSON types.,operator__less}

Since: version 1.0.0

Definition at line 22933 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>

bool operator<	(	const ScalarType	lhs,
		const_reference	rhs
	)

friend

comparison: less than

comparison: less than Compares whether one JSON value lhs is less than another JSON value rhs according to the following rules:

If lhs and rhs have the same type, the values are compared using the default < operator.
Integer and floating-point numbers are automatically converted before comparison
In case lhs and rhs have different types, the values are ignored and the order of the types is considered, see operator<(const value_t, const value_t).

Parameters

[in]	lhs	first JSON value to consider
[in]	rhs	second JSON value to consider

Returns: whether lhs is less than rhs

Linear.

No-throw guarantee: this function never throws exceptions.

{The example demonstrates comparing several JSON types.,operator__less}

Since: version 1.0.0

Definition at line 22944 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

std::ostream& operator<<	(	std::ostream &	o,
		const basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType > &	j
	)

friend

serialize to stream

Serialize the given JSON value j to the output stream o. The JSON value will be serialized using the dump member function.

The indentation of the output can be controlled with the member variable width of the output stream o. For instance, using the manipulator std::setw(4) on o sets the indentation level to 4 and the serialization result is the same as calling dump(4).
The indentation character can be controlled with the member variable fill of the output stream o. For instance, the manipulator `std::setfill('\t')` sets indentation to use a tab character rather than the default space character.

Parameters

[in,out]	o	stream to serialize to
[in]	j	JSON value to serialize

Returns: the stream o

Exceptions

type_error.316 if a string stored inside the JSON value is not UTF-8 encoded

Linear.

{The example below shows the serialization with different parameters to width to adjust the indentation level.,operator_serialize}

Since: version 1.0.0; indentation character added in version 3.0.0

Definition at line 23127 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

std::istream& operator<<	(	basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType > &	j,
		std::istream &	i
	)

friend

deserialize from stream

Deprecated:: This stream operator is deprecated and will be removed in version 4.0.0 of the library. Please use operator>>(std::istream&, basic_json&) instead; that is, replace calls like j << i; with i >> j;.

Since: version 1.0.0; deprecated since version 3.0.0

Definition at line 23421 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

bool operator<=	(	const_reference	lhs,
		const_reference	rhs
	)

friend

comparison: less than or equal

Compares whether one JSON value lhs is less than or equal to another JSON value by calculating not (rhs < lhs).

Parameters

[in]	lhs	first JSON value to consider
[in]	rhs	second JSON value to consider

Returns: whether lhs is less than or equal to rhs

Linear.

No-throw guarantee: this function never throws exceptions.

{The example demonstrates comparing several JSON types.,operator__greater}

Since: version 1.0.0

Definition at line 22968 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>

bool operator<=	(	const_reference	lhs,
		const ScalarType	rhs
	)

friend

comparison: less than or equal

comparison: less than or equal Compares whether one JSON value lhs is less than or equal to another JSON value by calculating not (rhs < lhs).

Parameters

[in]	lhs	first JSON value to consider
[in]	rhs	second JSON value to consider

Returns: whether lhs is less than or equal to rhs

Linear.

No-throw guarantee: this function never throws exceptions.

{The example demonstrates comparing several JSON types.,operator__greater}

Since: version 1.0.0

Definition at line 22979 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>

bool operator<=	(	const ScalarType	lhs,
		const_reference	rhs
	)

friend

comparison: less than or equal

comparison: less than or equal Compares whether one JSON value lhs is less than or equal to another JSON value by calculating not (rhs < lhs).

Parameters

[in]	lhs	first JSON value to consider
[in]	rhs	second JSON value to consider

Returns: whether lhs is less than or equal to rhs

Linear.

No-throw guarantee: this function never throws exceptions.

{The example demonstrates comparing several JSON types.,operator__greater}

Since: version 1.0.0

Definition at line 22990 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

bool operator==	(	const_reference	lhs,
		const_reference	rhs
	)

friend

comparison: equal

Compares two JSON values for equality according to the following rules:

Two JSON values are equal if (1) they are from the same type and (2) their stored values are the same according to their respective operator==.
Integer and floating-point numbers are automatically converted before comparison. Note that two NaN values are always treated as unequal.
Two JSON null values are equal.

Note: Floating-point inside JSON values numbers are compared with json::number_float_t::operator== which is double::operator== by default. To compare floating-point while respecting an epsilon, an alternative comparison function could be used, for instance
template<typename T, typename = typename std::enable_if<std::is_floating_point<T>::value, T>::type>
inline bool is_same(T a, T b, T epsilon = std::numeric_limits<T>::epsilon()) noexcept
{
return std::abs(a - b) <= epsilon;
}
Or you can self-defined operator equal function like this:
bool my_equal(const_reference lhs, const_reference rhs) {
const auto lhs_type lhs.type();
const auto rhs_type rhs.type();
if (lhs_type == rhs_type) {
switch(lhs_type)
// self_defined case
case value_t::number_float:
return std::abs(lhs - rhs) <= std::numeric_limits<float>::epsilon();
// other cases remain the same with the original
...
}
...
}; NaN values never compare equal to themselves or to other NaN values.

Parameters

[in]	lhs	first JSON value to consider
[in]	rhs	second JSON value to consider

Returns: whether the values lhs and rhs are equal

No-throw guarantee: this function never throws exceptions.

Linear.

{The example demonstrates comparing several JSON types.,operator__equal}

Since: version 1.0.0

Definition at line 22693 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>

bool operator==	(	const_reference	lhs,
		const ScalarType	rhs
	)

friend

comparison: equal

comparison: equal Compares two JSON values for equality according to the following rules:

Two JSON values are equal if (1) they are from the same type and (2) their stored values are the same according to their respective operator==.
Integer and floating-point numbers are automatically converted before comparison. Note that two NaN values are always treated as unequal.
Two JSON null values are equal.

Note: Floating-point inside JSON values numbers are compared with json::number_float_t::operator== which is double::operator== by default. To compare floating-point while respecting an epsilon, an alternative comparison function could be used, for instance
template<typename T, typename = typename std::enable_if<std::is_floating_point<T>::value, T>::type>
inline bool is_same(T a, T b, T epsilon = std::numeric_limits<T>::epsilon()) noexcept
{
return std::abs(a - b) <= epsilon;
}
Or you can self-defined operator equal function like this:
bool my_equal(const_reference lhs, const_reference rhs) {
const auto lhs_type lhs.type();
const auto rhs_type rhs.type();
if (lhs_type == rhs_type) {
switch(lhs_type)
// self_defined case
case value_t::number_float:
return std::abs(lhs - rhs) <= std::numeric_limits<float>::epsilon();
// other cases remain the same with the original
...
}
...
}; NaN values never compare equal to themselves or to other NaN values.

Parameters

[in]	lhs	first JSON value to consider
[in]	rhs	second JSON value to consider

Returns: whether the values lhs and rhs are equal

No-throw guarantee: this function never throws exceptions.

Linear.

{The example demonstrates comparing several JSON types.,operator__equal}

Since: version 1.0.0

Definition at line 22767 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>

bool operator==	(	const ScalarType	lhs,
		const_reference	rhs
	)

friend

comparison: equal

comparison: equal Compares two JSON values for equality according to the following rules:

Two JSON values are equal if (1) they are from the same type and (2) their stored values are the same according to their respective operator==.
Integer and floating-point numbers are automatically converted before comparison. Note that two NaN values are always treated as unequal.
Two JSON null values are equal.

Note: Floating-point inside JSON values numbers are compared with json::number_float_t::operator== which is double::operator== by default. To compare floating-point while respecting an epsilon, an alternative comparison function could be used, for instance
template<typename T, typename = typename std::enable_if<std::is_floating_point<T>::value, T>::type>
inline bool is_same(T a, T b, T epsilon = std::numeric_limits<T>::epsilon()) noexcept
{
return std::abs(a - b) <= epsilon;
}
Or you can self-defined operator equal function like this:
bool my_equal(const_reference lhs, const_reference rhs) {
const auto lhs_type lhs.type();
const auto rhs_type rhs.type();
if (lhs_type == rhs_type) {
switch(lhs_type)
// self_defined case
case value_t::number_float:
return std::abs(lhs - rhs) <= std::numeric_limits<float>::epsilon();
// other cases remain the same with the original
...
}
...
}; NaN values never compare equal to themselves or to other NaN values.

Parameters

[in]	lhs	first JSON value to consider
[in]	rhs	second JSON value to consider

Returns: whether the values lhs and rhs are equal

No-throw guarantee: this function never throws exceptions.

Linear.

{The example demonstrates comparing several JSON types.,operator__equal}

Since: version 1.0.0

Definition at line 22778 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

bool operator>	(	const_reference	lhs,
		const_reference	rhs
	)

friend

comparison: greater than

Compares whether one JSON value lhs is greater than another JSON value by calculating not (lhs <= rhs).

Parameters

[in]	lhs	first JSON value to consider
[in]	rhs	second JSON value to consider

Returns: whether lhs is greater than to rhs

Linear.

No-throw guarantee: this function never throws exceptions.

{The example demonstrates comparing several JSON types.,operator__lessequal}

Since: version 1.0.0

Definition at line 23014 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>

bool operator>	(	const_reference	lhs,
		const ScalarType	rhs
	)

friend

comparison: greater than

comparison: greater than Compares whether one JSON value lhs is greater than another JSON value by calculating not (lhs <= rhs).

Parameters

[in]	lhs	first JSON value to consider
[in]	rhs	second JSON value to consider

Returns: whether lhs is greater than to rhs

Linear.

No-throw guarantee: this function never throws exceptions.

{The example demonstrates comparing several JSON types.,operator__lessequal}

Since: version 1.0.0

Definition at line 23025 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>

bool operator>	(	const ScalarType	lhs,
		const_reference	rhs
	)

friend

comparison: greater than

comparison: greater than Compares whether one JSON value lhs is greater than another JSON value by calculating not (lhs <= rhs).

Parameters

[in]	lhs	first JSON value to consider
[in]	rhs	second JSON value to consider

Returns: whether lhs is greater than to rhs

Linear.

No-throw guarantee: this function never throws exceptions.

{The example demonstrates comparing several JSON types.,operator__lessequal}

Since: version 1.0.0

Definition at line 23036 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

bool operator>=	(	const_reference	lhs,
		const_reference	rhs
	)

friend

comparison: greater than or equal

Compares whether one JSON value lhs is greater than or equal to another JSON value by calculating not (lhs < rhs).

Parameters

[in]	lhs	first JSON value to consider
[in]	rhs	second JSON value to consider

Returns: whether lhs is greater than or equal to rhs

Linear.

No-throw guarantee: this function never throws exceptions.

{The example demonstrates comparing several JSON types.,operator__greaterequal}

Since: version 1.0.0

Definition at line 23060 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>

bool operator>=	(	const_reference	lhs,
		const ScalarType	rhs
	)

friend

comparison: greater than or equal

comparison: greater than or equal Compares whether one JSON value lhs is greater than or equal to another JSON value by calculating not (lhs < rhs).

Parameters

[in]	lhs	first JSON value to consider
[in]	rhs	second JSON value to consider

Returns: whether lhs is greater than or equal to rhs

Linear.

No-throw guarantee: this function never throws exceptions.

{The example demonstrates comparing several JSON types.,operator__greaterequal}

Since: version 1.0.0

Definition at line 23071 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>

bool operator>=	(	const ScalarType	lhs,
		const_reference	rhs
	)

friend

comparison: greater than or equal

comparison: greater than or equal Compares whether one JSON value lhs is greater than or equal to another JSON value by calculating not (lhs < rhs).

Parameters

[in]	lhs	first JSON value to consider
[in]	rhs	second JSON value to consider

Returns: whether lhs is greater than or equal to rhs

Linear.

No-throw guarantee: this function never throws exceptions.

{The example demonstrates comparing several JSON types.,operator__greaterequal}

Since: version 1.0.0

Definition at line 23082 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

std::ostream& operator>>	(	const basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType > &	j,
		std::ostream &	o
	)

friend

serialize to stream

Deprecated:: This stream operator is deprecated and will be removed in future 4.0.0 of the library. Please use operator<<(std::ostream&, const basic_json&) instead; that is, replace calls like j >> o; with o << j;.

Since: version 1.0.0; deprecated since version 3.0.0

Definition at line 23151 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

std::istream& operator>>	(	std::istream &	i,
		basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType > &	j
	)

friend

deserialize from stream

Deserializes an input stream to a JSON value.

Parameters

[in,out]	i	input stream to read a serialized JSON value from
[in,out]	j	JSON value to write the deserialized input to

Exceptions

parse_error.101	in case of an unexpected token
parse_error.102	if to_unicode fails or surrogate error
parse_error.103	if to_unicode fails

Linear in the length of the input. The parser is a predictive LL(1) parser.

Note: A UTF-8 byte order mark is silently ignored.

{The example below shows how a JSON value is constructed by reading a serialization from a stream.,operator_deserialize}

See also: parse(std::istream&, const parser_callback_t) for a variant with a parser callback function to filter values while parsing

Since: version 1.0.0

Definition at line 23451 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

void swap	(	reference	left,
		reference	right
	)

friend

exchanges the values

Exchanges the contents of the JSON value from left with those of right. Does not invoke any move, copy, or swap operations on individual elements. All iterators and references remain valid. The past-the-end iterator is invalidated. implemented as a friend function callable via ADL.

Parameters

[in,out]	left	JSON value to exchange the contents with
[in,out]	right	JSON value to exchange the contents with

Constant.

{The example below shows how JSON values can be swapped with swap().,swap__reference}

Since: version 1.0.0

Definition at line 22472 of file json.hpp.

Member Data Documentation

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

JSON_PRIVATE_UNLESS_TESTED nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::__pad0__

private

Definition at line 16760 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

JSON_PRIVATE_UNLESS_TESTED nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::__pad1__

private

Definition at line 16792 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

JSON_PRIVATE_UNLESS_TESTED nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::__pad2__

private

Definition at line 17535 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

JSON_PRIVATE_UNLESS_TESTED nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::__pad3__

Definition at line 23527 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

array_t* nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::array

private

array (stored with pointer to save storage)

Definition at line 17537 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

binary_t* nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::binary

private

binary (stored with pointer to save storage)

Definition at line 17541 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

boolean_t nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::boolean

private

boolean

Definition at line 17543 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

json_value nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::m_value = {}

the value of the current element

Definition at line 23530 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

number_float_t nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::number_float

private

number (floating-point)

Definition at line 17549 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

number_integer_t nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::number_integer

private

number (integer)

Definition at line 17545 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

number_unsigned_t nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::number_unsigned

private

number (unsigned integer)

Definition at line 17547 of file json.hpp.

template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

string_t* nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::string

private

string (stored with pointer to save storage)

Definition at line 17539 of file json.hpp.

The documentation for this class was generated from the following file:

json.hpp

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