eagine::optional_reference_wrapper< T > Class Template Reference

Optional reference to an instance of type T. More...

#include <eagine/optional_ref.hpp>

Public Member Functions
	optional_reference_wrapper (T &ref) noexcept
	Construction from a reference to value of type T.
	optional_reference_wrapper (optional_reference_wrapper &&) noexcept=default
	Move constructor.
	optional_reference_wrapper (const optional_reference_wrapper &)=default
	Copy constructor.
auto	operator= (optional_reference_wrapper &&) noexcept -> optional_reference_wrapper &=default
	Move assignment operator.
auto	operator= (const optional_reference_wrapper &) -> optional_reference_wrapper &=default
	Copy assignment operator.
constexpr	optional_reference_wrapper (nothing_t) noexcept
	Construction from nothing. More...
constexpr	optional_reference_wrapper (std::nullptr_t) noexcept
	Construction from nullptr. More...
auto	is_valid () const noexcept -> bool
	Indicates if this stores a valid reference.
	operator bool () const noexcept
	Indicates if this stores a valid reference. More...
auto	get () const noexcept -> T &
	Returns the stored reference. More...
auto	value () const noexcept -> const T &
	Returns the stored value. More...
template<typename U >
auto	value_or (U &&fallback) const noexcept -> std::enable_if_t< std::is_convertible_v< U, T >, T >
	Returns the stored value if valid or fallback otherwise. More...
	operator T& () const noexcept
	Returns the stored reference. More...

Friends
auto	operator== (const optional_reference_wrapper &l, const T &r) -> tribool
	Tri-state equality comparison of the referred instance with a value.
auto	operator!= (const optional_reference_wrapper &l, const T &r) -> tribool
	Tri-state nonequality comparison of the referred instance with a value.

Detailed Description

template<typename T>
class eagine::optional_reference_wrapper< T >

Optional reference to an instance of type T.

See also

valid_if

Constructor & Destructor Documentation

optional_reference_wrapper() [1/2]

template<typename T >

constexpr eagine::optional_reference_wrapper< T >::optional_reference_wrapper ( nothing_t  )

inlineconstexprnoexcept

Construction from nothing.

Postcondition

!is_valid()

optional_reference_wrapper() [2/2]

template<typename T >

constexpr eagine::optional_reference_wrapper< T >::optional_reference_wrapper ( std::nullptr_t  )

inlineconstexprnoexcept

Construction from nullptr.

Postcondition

!is_valid()

Member Function Documentation

get()

template<typename T >

auto eagine::optional_reference_wrapper< T >::get ( ) const -> T&

inlinenoexcept

Returns the stored reference.

Precondition

is_valid()

Referenced by eagine::optional_reference_wrapper< T >::operator T&().

operator bool()

template<typename T >

eagine::optional_reference_wrapper< T >::operator bool ( ) const

inlineexplicitnoexcept

Indicates if this stores a valid reference.

See also

is_valid

operator T&()

template<typename T >

eagine::optional_reference_wrapper< T >::operator T& ( ) const

inlineexplicitnoexcept

Returns the stored reference.

See also

get

value()

template<typename T >

auto eagine::optional_reference_wrapper< T >::value ( ) const -> const T&

inlinenoexcept

Returns the stored value.

Precondition

is_valid()

value_or()

template<typename T >

template<typename U >

auto eagine::optional_reference_wrapper< T >::value_or ( U &&  fallback ) const -> std::enable_if_t<std::is_convertible_v<U, T>, T>

inlinenoexcept

Returns the stored value if valid or fallback otherwise.

See also

is_valid

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

• eagine/optional_ref.hpp