Template Class optional< T & >

Defined in File tl-optional.hpp

Class Documentation

template<class T> class optional<T&>

Specialization for when T is a reference. optional<T&> acts similarly to a T*, but provides more operations and shows intent more clearly.

Public Types

using value_type = T&

Public Functions

template<class F> inline TL_OPTIONAL_11_CONSTEXPR detail::invoke_result_t< F, T & > and_then (F &&f) &: Carries out some operation which returns an optional on the stored object if there is one.

template<class F> inline TL_OPTIONAL_11_CONSTEXPR detail::invoke_result_t< F, T & > and_then (F &&f) &&

template<class F> inline constexpr detail::invoke_result_t<F, const T&> and_then(F &&f) const &

template<class F> inline constexpr detail::invoke_result_t<F, const T&> and_then(F &&f) const &&

template<class F, detail::enable_if_ret_void< F > * = nullptr> inline optional< T > TL_OPTIONAL_11_CONSTEXPR or_else (F &&f) &: Calls f if the optional is empty.

template<class F, detail::disable_if_ret_void< F > * = nullptr> inline optional< T > TL_OPTIONAL_11_CONSTEXPR or_else (F &&f) &

template<class F, detail::enable_if_ret_void<F>* = nullptr> inline optional<T> or_else(F &&f) &&

template<class F, detail::disable_if_ret_void< F > * = nullptr> inline optional< T > TL_OPTIONAL_11_CONSTEXPR or_else (F &&f) &&

template<class F, detail::enable_if_ret_void<F>* = nullptr> inline optional<T> or_else(F &&f) const &

template<class F, detail::disable_if_ret_void< F > * = nullptr> inline optional< T > TL_OPTIONAL_11_CONSTEXPR or_else (F &&f) const &

template<class F, detail::enable_if_ret_void<F>* = nullptr> inline optional<T> or_else(F &&f) const &&

template<class F, detail::disable_if_ret_void<F>* = nullptr> inline optional<T> or_else(F &&f) const &&

template<class F, class U> inline U map_or(F &&f, U &&u) &: Maps the stored value with f if there is one, otherwise returns u

template<class F, class U> inline U map_or(F &&f, U &&u) &&

template<class F, class U> inline U map_or(F &&f, U &&u) const &

template<class F, class U> inline U map_or(F &&f, U &&u) const &&

template<class F, class U> inline detail::invoke_result_t map_or_else(F &&f, U &&u) &: Maps the stored value with f if there is one, otherwise calls u and returns the result.

template<class F, class U> inline detail::invoke_result_t map_or_else(F &&f, U &&u) &&

template<class F, class U> inline detail::invoke_result_t map_or_else(F &&f, U &&u) const &

template<class F, class U> inline detail::invoke_result_t map_or_else(F &&f, U &&u) const &&

template<class U> inline constexpr optional<typename std::decay::type> conjunction(U &&u) const: Returns u if *this has a value, otherwise an empty optional.

inline TL_OPTIONAL_11_CONSTEXPR optional disjunction (const optional &rhs) &: Returns rhs if *this is empty, otherwise the current value.

inline constexpr optional disjunction(const optional &rhs) const &

inline TL_OPTIONAL_11_CONSTEXPR optional disjunction (const optional &rhs) &&

inline constexpr optional disjunction(const optional &rhs) const &&

inline TL_OPTIONAL_11_CONSTEXPR optional disjunction (optional &&rhs) &

inline constexpr optional disjunction(optional &&rhs) const &

inline TL_OPTIONAL_11_CONSTEXPR optional disjunction (optional &&rhs) &&

inline constexpr optional disjunction(optional &&rhs) const &&

inline optional take(): Takes the value out of the optional, leaving it empty.

inline constexpr optional() noexcept: Constructs an optional that does not contain a value.

inline constexpr optional(nullopt_t) noexcept

TL_OPTIONAL_11_CONSTEXPR optional(const optional &rhs) noexcept = default

Copy constructor

If rhs contains a value, the stored value is direct-initialized with it. Otherwise, the constructed optional is empty.

TL_OPTIONAL_11_CONSTEXPR optional(optional &&rhs) = default

Move constructor

If rhs contains a value, the stored value is direct-initialized with it. Otherwise, the constructed optional is empty.

template<class U = T, detail::enable_if_t<!detail::is_optional<detail::decay_t>::value>* = nullptr> inline constexpr optional(U &&u) noexcept: Constructs the stored value with u.

template<class U> inline explicit constexpr optional(const optional &rhs) noexcept

~optional() = default: No-op.

inline optional &operator=(nullopt_t) noexcept

Assignment to empty.

Destroys the current value if there is one.

optional &operator=(const optional &rhs) = default

Copy assignment.

Rebinds this optional to the referee of rhs if there is one. Otherwise resets the stored value in *this.

template<class U = T, detail::enable_if_t<!detail::is_optional<detail::decay_t>::value>* = nullptr> inline optional &operator=(U &&u): Rebinds this optional to u.

template<class U> inline optional &operator=(const optional &rhs) noexcept

Converting copy assignment operator.

Rebinds this optional to the referee of rhs if there is one. Otherwise resets the stored value in *this.

template<class U = T, detail::enable_if_t<!detail::is_optional<detail::decay_t>::value>* = nullptr> inline optional &emplace(U &&u) noexcept: Rebinds this optional to u.

inline void swap(optional &rhs) noexcept

inline constexpr const T *operator->() const noexcept: Returns a pointer to the stored value.

inline TL_OPTIONAL_11_CONSTEXPR T * operator-> () noexcept

inline TL_OPTIONAL_11_CONSTEXPR T & operator* () noexcept: Returns the stored value.

inline constexpr const T &operator*() const noexcept

inline constexpr bool has_value() const noexcept

inline explicit constexpr operator bool() const noexcept

inline TL_OPTIONAL_11_CONSTEXPR T & value (): Returns the contained value if there is one, otherwise throws bad_optional_access

inline TL_OPTIONAL_11_CONSTEXPR const T & value () const

template<class U> inline constexpr T value_or(U &&u) const & noexcept: Returns the stored value if there is one, otherwise returns u

template<class U> inline TL_OPTIONAL_11_CONSTEXPR T value_or (U &&u) &&noexcept: \group value_or

inline void reset() noexcept: Destroys the stored value if one exists, making the optional empty.

Public Members

template<class F> TL_OPTIONAL_11_CONSTEXPR decltype(detail::optional_map_impl(std::declval< optional & >(), std::declval< F && >())) map (F &&f) &: Carries out some operation on the stored object if there is one.

template<class F> TL_OPTIONAL_11_CONSTEXPR decltype(detail::optional_map_impl(std::declval< optional && >(), std::declval< F && >())) map (F &&f) &&

template<class F> constexpr decltype(detail::optional_map_impl(std::declval<const optional&>(), std::declval<F&&>())) map(F &&f) const &

template<class F> constexpr decltype(detail::optional_map_impl(std::declval<const optional&&>(), std::declval<F&&>())) map(F &&f) const &&

template<class F> TL_OPTIONAL_11_CONSTEXPR decltype(detail::optional_map_impl(std::declval< optional & >(), std::declval< F && >())) transform (F &&f) &: Carries out some operation on the stored object if there is one.

template<class F> TL_OPTIONAL_11_CONSTEXPR decltype(detail::optional_map_impl(std::declval< optional && >(), std::declval< F && >())) transform (F &&f) &&: \group map \synopsis template <class F> auto transform(F &&f) &&;

template<class F> constexpr decltype(detail::optional_map_impl(std::declval<const optional&>(), std::declval<F&&>())) transform(F &&f) const &

template<class F> constexpr decltype(detail::optional_map_impl(std::declval<const optional&&>(), std::declval<F&&>())) transform(F &&f) const &&