rti::core::optional_value< T > Class Template Reference

<<extension>> Represents a value that can be initialized or not More...

#include <OptionalValue.hpp>

Public Member Functions
	optional_value ()
	Creates an uninitialized value. More...
	optional_value (const T &value)
	Creates an instance with a value. More...
	optional_value (bool condition, const T &value)
	Conditionally creates an instance that can be uninitialized or initialized with a value. More...
	optional_value (const optional_value< T > &other)
	Copy constructor. More...
bool	is_set () const OMG_NOEXCEPT
	Returns true only if the value is initialized. More...
bool	has_value () const OMG_NOEXCEPT
	Returns true only if the value is initialized. More...
	operator bool () const OMG_NOEXCEPT
	<<C++11>> Returns has_value() More...
void	reset ()
	After calling this function, this optional_value is not set. More...
const T &	value () const
	Retrieves the underlying object if it exists. More...
T &	value ()
	Retrieves the underlying object if it exists. More...
const T &	get () const
	Retrieves the underlying object if it exists. More...
T &	get ()
	Retrieves the underlying object if it exists. More...
const T &	operator* () const
T &	operator* ()
const T *	operator-> () const
T *	operator-> ()

Friends
void	swap (optional_value< T > &left, optional_value< T > &right) OMG_NOEXCEPT
	Swaps the underlying objects. More...

Detailed Description

template<typename T>
class rti::core::optional_value< T >

<<extension>> Represents a value that can be initialized or not

This class is similar to dds::core::optional and std::optional.

They have different implementations. dds::core::optional is only used in IDL-generated types, while rti::core::optional_value is used in parts of the API.

Constructor & Destructor Documentation

optional_value() [1/4]

template<typename T >

rti::core::optional_value< T >::optional_value ( )

inline

Creates an uninitialized value.

optional_value() [2/4]

template<typename T >

rti::core::optional_value< T >::optional_value ( const T &  value )

inline

Creates an instance with a value.

optional_value() [3/4]

template<typename T >

rti::core::optional_value< T >::optional_value ( bool  condition, const T &  value  )

inline

Conditionally creates an instance that can be uninitialized or initialized with a value.

Parameters

condition	If it is true it assigns value, otherwise this optional_value is uninitialized
value	The value to use if condition is true.

References rti::core::optional_value< T >::value().

optional_value() [4/4]

template<typename T >

rti::core::optional_value< T >::optional_value ( const optional_value< T > &  other )

inline

Copy constructor.

This optional_value will be initialized only if other is initialized.

References rti::core::optional_value< T >::get(), and rti::core::optional_value< T >::has_value().

Member Function Documentation

is_set()

template<typename T >

bool rti::core::optional_value< T >::is_set ( ) const

inline

Returns true only if the value is initialized.

[DEPRECATED] Use has_value()

has_value()

template<typename T >

bool rti::core::optional_value< T >::has_value ( ) const

inline

Returns true only if the value is initialized.

Referenced by rti::core::optional_value< T >::optional_value(), and rti::core::optional_value< T >::value().

operator bool()

template<typename T >

rti::core::optional_value< T >::operator bool ( ) const

inlineexplicit

<<C++11>> Returns has_value()

reset()

template<typename T >

void rti::core::optional_value< T >::reset ( )

inline

After calling this function, this optional_value is not set.

value() [1/2]

template<typename T >

const T & rti::core::optional_value< T >::value ( ) const

inline

Retrieves the underlying object if it exists.

This operation, unlike operator* throws an exception if the underlying object doesn't exist.

Exceptions

dds::core::PreconditionNotMetError

if !has_value().

References rti::core::optional_value< T >::has_value().

Referenced by rti::core::optional_value< T >::get(), rti::core::optional_value< T >::operator->(), and rti::core::optional_value< T >::optional_value().

value() [2/2]

template<typename T >

T & rti::core::optional_value< T >::value ( )

inline

Retrieves the underlying object if it exists.

This operation, unlike operator* throws an exception if the underlying object doesn't exist.

Exceptions

dds::core::PreconditionNotMetError

if !has_value().

References rti::core::optional_value< T >::has_value().

get() [1/2]

template<typename T >

const T & rti::core::optional_value< T >::get ( ) const

inline

Retrieves the underlying object if it exists.

[DEPRECATED] Use value() or operator*

Exceptions

dds::core::PreconditionNotMetError

if !has_value().

References rti::core::optional_value< T >::value().

Referenced by rti::core::optional_value< T >::optional_value().

get() [2/2]

template<typename T >

T & rti::core::optional_value< T >::get ( )

inline

Retrieves the underlying object if it exists.

[DEPRECATED] Use value() or operator*

Exceptions

dds::core::PreconditionNotMetError

if !has_value().

References rti::core::optional_value< T >::value().

operator*() [1/2]

template<typename T >

const T & rti::core::optional_value< T >::operator* ( ) const

inline

Get the value, without checking if it exists

Precondition

has_value(), otherwise this operation has undefined behavior. See value().

operator*() [2/2]

template<typename T >

T & rti::core::optional_value< T >::operator* ( )

inline

Get the value, without checking if it exists

Precondition

has_value(), otherwise this operation has undefined behavior. See value().

operator->() [1/2]

template<typename T >

const T * rti::core::optional_value< T >::operator-> ( ) const

inline

Get the value.

Exceptions

dds::core::PreconditionNotMetError

if !has_value()

References rti::core::optional_value< T >::value().

operator->() [2/2]

template<typename T >

T * rti::core::optional_value< T >::operator-> ( )

inline

Get the value.

Exceptions

dds::core::PreconditionNotMetError

if !has_value()

References rti::core::optional_value< T >::value().

Friends And Related Function Documentation

swap

template<typename T >

void swap ( optional_value< T > &  left, optional_value< T > &  right  )

friend

Swaps the underlying objects.

It uses swap(*left, *right) if that function is defined for type T; otherwise it uses std::swap.