Class Message

• Defined in File message.hpp

Inheritance Relationships

Derived Types

• public ros_babel_fish::ArrayMessageBase (Class ArrayMessageBase)

• public ros_babel_fish::CompoundMessage (Class CompoundMessage)

• public ros_babel_fish::ValueMessage< T > (Template Class ValueMessage)

Class Documentation

class Message

Message representation used by BabelFish. Wraps the memory of an actual type erased ROS2 message. Changes will affect the message that can be sent using the ROS runtime.

Subclassed by ros_babel_fish::ArrayMessageBase, ros_babel_fish::CompoundMessage, ros_babel_fish::ValueMessage< T >

Public Functions

explicit Message(MessageType type, std::shared_ptr<void> data)

virtual ~Message()

inline MessageType type() const

template<typename T>
inline T value() const

Convenience method to obtain the content of a ValueMessage as the given type. A type conversion is done if the type doesn’t match exactly. If the target type can not fit the source type, a warning is printed.

Template Parameters:

T – The type as which the value is retrieved

Throws:

• BabelFishException – If the message is not a ValueMessage

• BabelFishException – If the type of the ValueMessage can not be casted to a different type which is the case for bool, std::string, ros::Time and ros::Duration

Returns:

The value casted to the given type T

template<typename T>
inline T &as()

Convenience method that casts the message to the given type. Example:

Message &msg = getMessage();
CompoundMessage &compound = msg.as<CompoundMessage>();

Template Parameters:

T – Target type

Throws:

BabelFishException – If the message can not be casted to the target type

Returns:

Message casted to the target type as reference

template<typename T>
inline const T &as() const

Convenience method that casts the message to the given type. Example:

Message &msg = getMessage();
CompoundMessage &compound = msg.as<CompoundMessage>();

Template Parameters:

T – Target type

Throws:

BabelFishException – If the message can not be casted to the target type

Returns:

Message casted to the target type as reference

bool isTime() const

Returns:

True if this message is a builtin_interfaces/Time message and can be cast to rclcpp::Time using the value method.

bool isDuration() const

Returns:

True if this message is a builtin_interfaces/Duration message and can be cast to rclcpp::Duration using the value method.

virtual Message &operator[](const std::string &key)

Convenience method to access the child with the given key of a CompoundMessage.

Parameters:

key – The name or path of the child

Throws:

BabelFishException – If child access by key is not supported.

Returns:

The child message accessed by the given key

virtual const Message &operator[](const std::string &key) const

Convenience method to access the child with the given key of a CompoundMessage.

Parameters:

key – The name or path of the child

Throws:

BabelFishException – If child access by key is not supported.

Returns:

The child message accessed by the given key

Message &operator=(bool value)

Message &operator=(uint8_t value)

Message &operator=(uint16_t value)

Message &operator=(uint32_t value)

Message &operator=(uint64_t value)

Message &operator=(int8_t value)

Message &operator=(int16_t value)

Message &operator=(int32_t value)

Message &operator=(int64_t value)

Message &operator=(float value)

Message &operator=(double value)

Message &operator=(long double value)

Message &operator=(const char *value)

Message &operator=(const std::string &value)

Message &operator=(const std::wstring &value)

Message &operator=(const builtin_interfaces::msg::Time &value)

Message &operator=(const builtin_interfaces::msg::Duration &value)

Message &operator=(const rclcpp::Time &value)

Message &operator=(const rclcpp::Duration &value)

Message &operator=(const Message &other)

template<typename T>
bool operator==(const T &other) const

bool operator==(const Message &other) const

bool operator==(const char *c) const

bool operator==(const wchar_t *c) const

template<typename T>
bool operator!=(const T &other) const

template<>
bool value() const

Protected Functions

inline void move(std::shared_ptr<void> new_data)

inline virtual void onMoved()

template<typename T, typename U>
void checkValueEqual(const U &other, bool &result) const

Message(const Message &other) = default

virtual bool _isMessageEqual(const Message &other) const = 0

virtual void _assign(const Message &other) = 0

inline unsigned char *data_ptr()

inline const unsigned char *data_ptr() const

Protected Attributes

std::shared_ptr<void> data_

MessageType type_

Friends

friend class CompoundMessage

friend class CompoundArrayMessage_