table of contents
std::experimental::optional< _Tp >(3) | Library Functions Manual | std::experimental::optional< _Tp >(3) |
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 operator bool () const noexcept
constexpr const _Tp & operator* () const &
constexpr _Tp & operator* () &
constexpr _Tp && operator* () &&
constexpr const _Tp && operator* () const &&
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¶
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Fri May 24 2024 | libstdc++ |