utils::optional_reference< T > Class Template Reference

A simple wrapper class for optional reference types. More...

#include <optional_reference.hpp>

Public Member Functions
	optional_reference ()=default
	optional_reference (T &ref)
	optional_reference (std::nullopt_t)
T &	value () const
optional_reference< T > &	operator= (T &new_ref)
	operator bool () const
T *	ptr () const
	Returns a pointer to the referenced object or nullptr if no reference is held. More...
T *	operator-> () const
T &	operator* () const

Private Attributes
std::optional< std::reference_wrapper< T > >	opt_

Detailed Description

template<typename T>
class utils::optional_reference< T >

A simple wrapper class for optional reference types.

Since std::optional (as of C++17 at least) does not support reference types (see [1]), the only way to use those is std::optional<std::reference_wrapper>. However, this makes the interace messy, as to access the referenced object you need an extra get() call to access the value stored in the reference wrapper.

This does not rebind operator=() as std::optional does. Instead, assigning a value to this object will simply change the object to which it points. To change the value of the referred to object, use value() or one of the other operators.

[1] https://www.fluentcpp.com/2018/10/05/pros-cons-optional-references/

Definition at line 36 of file optional_reference.hpp.

Constructor & Destructor Documentation

optional_reference() [1/3]

template<typename T>

utils::optional_reference< T >::optional_reference ( )

default

optional_reference() [2/3]

template<typename T>

utils::optional_reference< T >::optional_reference ( T &  ref )

inline

Definition at line 41 of file optional_reference.hpp.

optional_reference() [3/3]

template<typename T>

utils::optional_reference< T >::optional_reference ( std::nullopt_t  )

inline

Definition at line 46 of file optional_reference.hpp.

Member Function Documentation

operator bool()

template<typename T>

utils::optional_reference< T >::operator bool ( ) const

inline

Definition at line 72 of file optional_reference.hpp.

operator*()

template<typename T>

T& utils::optional_reference< T >::operator* ( ) const

inline

Definition at line 92 of file optional_reference.hpp.

operator->()

template<typename T>

T* utils::optional_reference< T >::operator-> ( ) const

inline

Definition at line 87 of file optional_reference.hpp.

operator=()

template<typename T>

optional_reference<T>& utils::optional_reference< T >::operator= ( T &  new_ref )

inline

Definition at line 66 of file optional_reference.hpp.

ptr()

template<typename T>

T* utils::optional_reference< T >::ptr ( ) const

inline

Returns a pointer to the referenced object or nullptr if no reference is held.

Definition at line 78 of file optional_reference.hpp.

value()

template<typename T>

T& utils::optional_reference< T >::value ( ) const

inline

Definition at line 51 of file optional_reference.hpp.

Referenced by utils::optional_reference< const unit_type >::operator*(), utils::optional_reference< const unit_type >::operator->(), and utils::optional_reference< const unit_type >::ptr().

Member Data Documentation

opt_

template<typename T>

std::optional<std::reference_wrapper<T> > utils::optional_reference< T >::opt_

private

Definition at line 98 of file optional_reference.hpp.

Referenced by utils::optional_reference< const unit_type >::operator bool(), utils::optional_reference< const unit_type >::operator=(), utils::optional_reference< const unit_type >::ptr(), and utils::optional_reference< const unit_type >::value().

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The documentation for this class was generated from the following file:

• utils/optional_reference.hpp