std::experimental::optional< _Tp >

Section: C Library Functions (3)
Updated: Wed Apr 17 2019
Page Index

NAME

std::experimental::optional< _Tp > - Class template for optional values.

SYNOPSIS

Inherits std::experimental::_Optional_base< _Tp >, and std::_Enable_copy_move< is_copy_constructible< _Tp >::value, __and_< is_copy_constructible< _Tp >, is_copy_assignable< _Tp > >::value, is_move_constructible< _Tp >::value, __and_< is_move_constructible< _Tp >, is_move_assignable< _Tp > >::value, optional< _Tp > >.

Public Types

using value_type = _Tp

Public Member Functions

template<typename _Up = _Tp, enable_if_t< __and_< __not_< is_same< optional< _Tp >, decay_t< _Up >>>, is_constructible< _Tp, _Up && >, is_convertible< _Up &&, _Tp > >::value, bool > = true> constexpr optional (_Up &&__t)

template<typename _Up = _Tp, enable_if_t< __and_< __not_< is_same< optional< _Tp >, decay_t< _Up >>>, is_constructible< _Tp, _Up && >, __not_< is_convertible< _Up &&, _Tp >> >::value, bool > = false> constexpr optional (_Up &&__t)

template<typename _Up , enable_if_t< __and_< __not_< is_same< _Tp, _Up >>, is_constructible< _Tp, const _Up & >, is_convertible< const _Up &, _Tp >, __not_< __converts_from_optional< _Tp, _Up >> >::value, bool > = true> constexpr optional (const optional< _Up > &__t)

template<typename _Up , enable_if_t< __and_< __not_< is_same< _Tp, _Up >>, is_constructible< _Tp, const _Up & >, __not_< is_convertible< const _Up &, _Tp >>, __not_< __converts_from_optional< _Tp, _Up >> >::value, bool > = false> constexpr optional (const optional< _Up > &__t)

template<typename _Up , enable_if_t< __and_< __not_< is_same< _Tp, _Up >>, is_constructible< _Tp, _Up && >, is_convertible< _Up &&, _Tp >, __not_< __converts_from_optional< _Tp, _Up >> >::value, bool > = true> constexpr optional (optional< _Up > &&__t)

template<typename _Up , enable_if_t< __and_< __not_< is_same< _Tp, _Up >>, is_constructible< _Tp, _Up && >, __not_< is_convertible< _Up &&, _Tp >>, __not_< __converts_from_optional< _Tp, _Up >> >::value, bool > = false> constexpr optional (optional< _Up > &&__t)

template<typename... _Args> enable_if_t< is_constructible< _Tp, _Args &&... >::value > emplace (_Args &&... __args)

template<typename _Up , typename... _Args> enable_if_t< is_constructible< _Tp, initializer_list< _Up > &, _Args &&... >::value > emplace (initializer_list< _Up > __il, _Args &&... __args)

constexpr const _Tp & operator * () const &

constexpr _Tp & operator * () &

constexpr _Tp && operator * () &&

constexpr const _Tp && operator * () const &&

constexpr operator bool () const noexcept

constexpr const _Tp * operator-> () const

_Tp * operator-> ()

optional & operator= (nullopt_t) noexcept

template<typename _Up = _Tp> enable_if_t< __and_< __not_< is_same< optional< _Tp >, decay_t< _Up > > >, is_constructible< _Tp, _Up >, __not_< __and_< is_scalar< _Tp >, is_same< _Tp, decay_t< _Up > > > >, is_assignable< _Tp &, _Up > >::value, optional & > operator= (_Up &&__u)

template<typename _Up > enable_if_t< __and_< __not_< is_same< _Tp, _Up > >, is_constructible< _Tp, const _Up & >, is_assignable< _Tp &, _Up >, __not_< __converts_from_optional< _Tp, _Up > >, __not_< __assigns_from_optional< _Tp, _Up > > >::value, optional & > operator= (const optional< _Up > &__u)

template<typename _Up > enable_if_t< __and_< __not_< is_same< _Tp, _Up > >, is_constructible< _Tp, _Up >, is_assignable< _Tp &, _Up >, __not_< __converts_from_optional< _Tp, _Up > >, __not_< __assigns_from_optional< _Tp, _Up > > >::value, optional & > operator= (optional< _Up > &&__u)

void swap (optional &__other) noexcept(is_nothrow_move_constructible< _Tp >() &&__is_nothrow_swappable< _Tp >::value)

constexpr const _Tp & value () const &

constexpr _Tp & value () &

constexpr _Tp && value () &&

constexpr const _Tp && value () const &&

template<typename _Up > constexpr _Tp value_or (_Up &&__u) const &

template<typename _Up > _Tp value_or (_Up &&__u) &&

Private Member Functions

void _M_construct (_Args &&... __args) noexcept(is_nothrow_constructible< _Stored_type, _Args... >())

void _M_destruct ()

constexpr _Tp & _M_get () noexcept

constexpr const _Tp & _M_get () const noexcept

constexpr bool _M_is_engaged () const noexcept

void _M_reset ()

Private Attributes

_Empty_byte _M_empty

_Stored_type _M_payload

Detailed Description

template<typename _Tp>

class std::experimental::optional< _Tp >" Class template for optional values.

Definition at line 81 of file optional.

Author

Generated automatically by Doxygen for libstdc++ from the source code.