.TH "std::experimental::optional< _Tp >" 3cxx "Thu Feb 16 2023" "libstdc++" \" -*- nroff -*-
.ad l
.nh
.SH NAME
std::experimental::optional< _Tp > \- Class template for optional values\&.  

.SH SYNOPSIS
.br
.PP
.PP
Inherits \fBstd::_Optional_base< _Tp, bool, bool >\fP, and _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 > >\&.
.SS "Public Types"

.in +1c
.ti -1c
.RI "using \fBvalue_type\fP = _Tp"
.br
.in -1c
.SS "Public Member Functions"

.in +1c
.ti -1c
.RI "template<typename _Up  = _Tp, \fBenable_if_t\fP< __and_< __not_< \fBis_same\fP< \fBoptional\fP< _Tp >, \fBdecay_t\fP< _Up > > >, \fBis_constructible\fP< _Tp, _Up && >, \fBis_convertible\fP< _Up &&, _Tp > >::value, bool >  = true> constexpr \fBoptional\fP (_Up &&__t)"
.br
.ti -1c
.RI "template<typename _Up  = _Tp, \fBenable_if_t\fP< __and_< __not_< \fBis_same\fP< \fBoptional\fP< _Tp >, \fBdecay_t\fP< _Up > > >, \fBis_constructible\fP< _Tp, _Up && >, __not_< \fBis_convertible\fP< _Up &&, _Tp > > >::value, bool >  = false> constexpr \fBoptional\fP (_Up &&__t)"
.br
.ti -1c
.RI "template<typename _Up , \fBenable_if_t\fP< __and_< __not_< \fBis_same\fP< _Tp, _Up > >, \fBis_constructible\fP< _Tp, const _Up & >, \fBis_convertible\fP< const _Up &, _Tp >, __not_< __converts_from_optional< _Tp, _Up > > >::value, bool >  = true> constexpr \fBoptional\fP (const \fBoptional\fP< _Up > &__t)"
.br
.ti -1c
.RI "template<typename _Up , \fBenable_if_t\fP< __and_< __not_< \fBis_same\fP< _Tp, _Up > >, \fBis_constructible\fP< _Tp, const _Up & >, __not_< \fBis_convertible\fP< const _Up &, _Tp > >, __not_< __converts_from_optional< _Tp, _Up > > >::value, bool >  = false> constexpr \fBoptional\fP (const \fBoptional\fP< _Up > &__t)"
.br
.ti -1c
.RI "template<typename _Up , \fBenable_if_t\fP< __and_< __not_< \fBis_same\fP< _Tp, _Up > >, \fBis_constructible\fP< _Tp, _Up && >, \fBis_convertible\fP< _Up &&, _Tp >, __not_< __converts_from_optional< _Tp, _Up > > >::value, bool >  = true> constexpr \fBoptional\fP (\fBoptional\fP< _Up > &&__t)"
.br
.ti -1c
.RI "template<typename _Up , \fBenable_if_t\fP< __and_< __not_< \fBis_same\fP< _Tp, _Up > >, \fBis_constructible\fP< _Tp, _Up && >, __not_< \fBis_convertible\fP< _Up &&, _Tp > >, __not_< __converts_from_optional< _Tp, _Up > > >::value, bool >  = false> constexpr \fBoptional\fP (\fBoptional\fP< _Up > &&__t)"
.br
.ti -1c
.RI "template<typename\&.\&.\&. _Args> \fBenable_if_t\fP< \fBis_constructible\fP< _Tp, _Args &&\&.\&.\&. >::value > \fBemplace\fP (_Args &&\&.\&.\&. __args)"
.br
.ti -1c
.RI "template<typename _Up , typename\&.\&.\&. _Args> \fBenable_if_t\fP< \fBis_constructible\fP< _Tp, \fBinitializer_list\fP< _Up > &, _Args &&\&.\&.\&. >::value > \fBemplace\fP (\fBinitializer_list\fP< _Up > __il, _Args &&\&.\&.\&. __args)"
.br
.ti -1c
.RI "constexpr \fBoperator bool\fP () const noexcept"
.br
.ti -1c
.RI "constexpr _Tp & \fBoperator*\fP () &"
.br
.ti -1c
.RI "constexpr _Tp && \fBoperator*\fP () &&"
.br
.ti -1c
.RI "constexpr const _Tp & \fBoperator*\fP () const &"
.br
.ti -1c
.RI "constexpr const _Tp && \fBoperator*\fP () const &&"
.br
.ti -1c
.RI "_Tp * \fBoperator\->\fP ()"
.br
.ti -1c
.RI "constexpr const _Tp * \fBoperator\->\fP () const"
.br
.ti -1c
.RI "template<typename _Up  = _Tp> \fBenable_if_t\fP< __and_< __not_< \fBis_same\fP< \fBoptional\fP< _Tp >, \fBdecay_t\fP< _Up > > >, \fBis_constructible\fP< _Tp, _Up >, __not_< __and_< \fBis_scalar\fP< _Tp >, \fBis_same\fP< _Tp, \fBdecay_t\fP< _Up > > > >, \fBis_assignable\fP< _Tp &, _Up > >::value, \fBoptional\fP & > \fBoperator=\fP (_Up &&__u)"
.br
.ti -1c
.RI "template<typename _Up > \fBenable_if_t\fP< __and_< __not_< \fBis_same\fP< _Tp, _Up > >, \fBis_constructible\fP< _Tp, const _Up & >, \fBis_assignable\fP< _Tp &, _Up >, __not_< __converts_from_optional< _Tp, _Up > >, __not_< __assigns_from_optional< _Tp, _Up > > >::value, \fBoptional\fP & > \fBoperator=\fP (const \fBoptional\fP< _Up > &__u)"
.br
.ti -1c
.RI "\fBoptional\fP & \fBoperator=\fP (\fBnullopt_t\fP) noexcept"
.br
.ti -1c
.RI "template<typename _Up > \fBenable_if_t\fP< __and_< __not_< \fBis_same\fP< _Tp, _Up > >, \fBis_constructible\fP< _Tp, _Up >, \fBis_assignable\fP< _Tp &, _Up >, __not_< __converts_from_optional< _Tp, _Up > >, __not_< __assigns_from_optional< _Tp, _Up > > >::value, \fBoptional\fP & > \fBoperator=\fP (\fBoptional\fP< _Up > &&__u)"
.br
.ti -1c
.RI "void \fBswap\fP (\fBoptional\fP &__other) noexcept(\fBis_nothrow_move_constructible\fP< _Tp >() &&__is_nothrow_swappable< _Tp >::value)"
.br
.ti -1c
.RI "constexpr _Tp & \fBvalue\fP () &"
.br
.ti -1c
.RI "constexpr _Tp && \fBvalue\fP () &&"
.br
.ti -1c
.RI "constexpr const _Tp & \fBvalue\fP () const &"
.br
.ti -1c
.RI "constexpr const _Tp && \fBvalue\fP () const &&"
.br
.ti -1c
.RI "template<typename _Up > _Tp \fBvalue_or\fP (_Up &&__u) &&"
.br
.ti -1c
.RI "template<typename _Up > constexpr _Tp \fBvalue_or\fP (_Up &&__u) const &"
.br
.in -1c
.SH "Detailed Description"
.PP 

.SS "template<typename _Tp>
.br
class std::experimental::optional< _Tp >"Class template for optional values\&. 
.PP
Definition at line \fB424\fP of file \fBexperimental/optional\fP\&.
.SH "Member Typedef Documentation"
.PP 
.SS "template<typename _Tp > using \fBstd::experimental::optional\fP< _Tp >::value_type =  _Tp"

.PP
Definition at line \fB447\fP of file \fBexperimental/optional\fP\&.
.SH "Constructor & Destructor Documentation"
.PP 
.SS "template<typename _Tp > template<typename _Up  = _Tp, \fBenable_if_t\fP< __and_< __not_< \fBis_same\fP< \fBoptional\fP< _Tp >, \fBdecay_t\fP< _Up > > >, \fBis_constructible\fP< _Tp, _Up && >, \fBis_convertible\fP< _Up &&, _Tp > >::value, bool >  = true> constexpr \fBstd::experimental::optional\fP< _Tp >::optional (_Up && __t)\fC [inline]\fP, \fC [constexpr]\fP"

.PP
Definition at line \fB460\fP of file \fBexperimental/optional\fP\&.
.SS "template<typename _Tp > template<typename _Up  = _Tp, \fBenable_if_t\fP< __and_< __not_< \fBis_same\fP< \fBoptional\fP< _Tp >, \fBdecay_t\fP< _Up > > >, \fBis_constructible\fP< _Tp, _Up && >, __not_< \fBis_convertible\fP< _Up &&, _Tp > > >::value, bool >  = false> constexpr \fBstd::experimental::optional\fP< _Tp >::optional (_Up && __t)\fC [inline]\fP, \fC [explicit]\fP, \fC [constexpr]\fP"

.PP
Definition at line \fB469\fP of file \fBexperimental/optional\fP\&.
.SS "template<typename _Tp > template<typename _Up , \fBenable_if_t\fP< __and_< __not_< \fBis_same\fP< _Tp, _Up > >, \fBis_constructible\fP< _Tp, const _Up & >, \fBis_convertible\fP< const _Up &, _Tp >, __not_< __converts_from_optional< _Tp, _Up > > >::value, bool >  = true> constexpr \fBstd::experimental::optional\fP< _Tp >::optional (const \fBoptional\fP< _Up > & __t)\fC [inline]\fP, \fC [constexpr]\fP"

.PP
Definition at line \fB479\fP of file \fBexperimental/optional\fP\&.
.SS "template<typename _Tp > template<typename _Up , \fBenable_if_t\fP< __and_< __not_< \fBis_same\fP< _Tp, _Up > >, \fBis_constructible\fP< _Tp, const _Up & >, __not_< \fBis_convertible\fP< const _Up &, _Tp > >, __not_< __converts_from_optional< _Tp, _Up > > >::value, bool >  = false> constexpr \fBstd::experimental::optional\fP< _Tp >::optional (const \fBoptional\fP< _Up > & __t)\fC [inline]\fP, \fC [explicit]\fP, \fC [constexpr]\fP"

.PP
Definition at line \fB492\fP of file \fBexperimental/optional\fP\&.
.SS "template<typename _Tp > template<typename _Up , \fBenable_if_t\fP< __and_< __not_< \fBis_same\fP< _Tp, _Up > >, \fBis_constructible\fP< _Tp, _Up && >, \fBis_convertible\fP< _Up &&, _Tp >, __not_< __converts_from_optional< _Tp, _Up > > >::value, bool >  = true> constexpr \fBstd::experimental::optional\fP< _Tp >::optional (\fBoptional\fP< _Up > && __t)\fC [inline]\fP, \fC [constexpr]\fP"

.PP
Definition at line \fB505\fP of file \fBexperimental/optional\fP\&.
.SS "template<typename _Tp > template<typename _Up , \fBenable_if_t\fP< __and_< __not_< \fBis_same\fP< _Tp, _Up > >, \fBis_constructible\fP< _Tp, _Up && >, __not_< \fBis_convertible\fP< _Up &&, _Tp > >, __not_< __converts_from_optional< _Tp, _Up > > >::value, bool >  = false> constexpr \fBstd::experimental::optional\fP< _Tp >::optional (\fBoptional\fP< _Up > && __t)\fC [inline]\fP, \fC [explicit]\fP, \fC [constexpr]\fP"

.PP
Definition at line \fB518\fP of file \fBexperimental/optional\fP\&.
.SH "Member Function Documentation"
.PP 
.SS "template<typename _Tp > template<typename\&.\&.\&. _Args> \fBenable_if_t\fP< \fBis_constructible\fP< _Tp, _Args &&\&.\&.\&. >::value > \fBstd::experimental::optional\fP< _Tp >::emplace (_Args &&\&.\&.\&. __args)\fC [inline]\fP"

.PP
Definition at line \fB603\fP of file \fBexperimental/optional\fP\&.
.SS "template<typename _Tp > template<typename _Up , typename\&.\&.\&. _Args> \fBenable_if_t\fP< \fBis_constructible\fP< _Tp, \fBinitializer_list\fP< _Up > &, _Args &&\&.\&.\&. >::value > \fBstd::experimental::optional\fP< _Tp >::emplace (\fBinitializer_list\fP< _Up > __il, _Args &&\&.\&.\&. __args)\fC [inline]\fP"

.PP
Definition at line \fB612\fP of file \fBexperimental/optional\fP\&.
.SS "template<typename _Tp > constexpr \fBstd::experimental::optional\fP< _Tp >::operator bool () const\fC [inline]\fP, \fC [explicit]\fP, \fC [constexpr]\fP, \fC [noexcept]\fP"

.PP
Definition at line \fB667\fP of file \fBexperimental/optional\fP\&.
.SS "template<typename _Tp > constexpr _Tp & \fBstd::experimental::optional\fP< _Tp >::operator* () &\fC [inline]\fP, \fC [constexpr]\fP"

.PP
Definition at line \fB656\fP of file \fBexperimental/optional\fP\&.
.SS "template<typename _Tp > constexpr _Tp && \fBstd::experimental::optional\fP< _Tp >::operator* () &&\fC [inline]\fP, \fC [constexpr]\fP"

.PP
Definition at line \fB660\fP of file \fBexperimental/optional\fP\&.
.SS "template<typename _Tp > constexpr const _Tp & \fBstd::experimental::optional\fP< _Tp >::operator* () const &\fC [inline]\fP, \fC [constexpr]\fP"

.PP
Definition at line \fB652\fP of file \fBexperimental/optional\fP\&.
.SS "template<typename _Tp > constexpr const _Tp && \fBstd::experimental::optional\fP< _Tp >::operator* () const &&\fC [inline]\fP, \fC [constexpr]\fP"

.PP
Definition at line \fB664\fP of file \fBexperimental/optional\fP\&.
.SS "template<typename _Tp > _Tp * \fBstd::experimental::optional\fP< _Tp >::operator\-> ()\fC [inline]\fP"

.PP
Definition at line \fB648\fP of file \fBexperimental/optional\fP\&.
.SS "template<typename _Tp > constexpr const _Tp * \fBstd::experimental::optional\fP< _Tp >::operator\-> () const\fC [inline]\fP, \fC [constexpr]\fP"

.PP
Definition at line \fB644\fP of file \fBexperimental/optional\fP\&.
.SS "template<typename _Tp > template<typename _Up  = _Tp> \fBenable_if_t\fP< __and_< __not_< \fBis_same\fP< \fBoptional\fP< _Tp >, \fBdecay_t\fP< _Up > > >, \fBis_constructible\fP< _Tp, _Up >, __not_< __and_< \fBis_scalar\fP< _Tp >, \fBis_same\fP< _Tp, \fBdecay_t\fP< _Up > > > >, \fBis_assignable\fP< _Tp &, _Up > >::value, \fBoptional\fP & > \fBstd::experimental::optional\fP< _Tp >::operator= (_Up && __u)\fC [inline]\fP"

.PP
Definition at line \fB540\fP of file \fBexperimental/optional\fP\&.
.SS "template<typename _Tp > template<typename _Up > \fBenable_if_t\fP< __and_< __not_< \fBis_same\fP< _Tp, _Up > >, \fBis_constructible\fP< _Tp, const _Up & >, \fBis_assignable\fP< _Tp &, _Up >, __not_< __converts_from_optional< _Tp, _Up > >, __not_< __assigns_from_optional< _Tp, _Up > > >::value, \fBoptional\fP & > \fBstd::experimental::optional\fP< _Tp >::operator= (const \fBoptional\fP< _Up > & __u)\fC [inline]\fP"

.PP
Definition at line \fB559\fP of file \fBexperimental/optional\fP\&.
.SS "template<typename _Tp > \fBoptional\fP & \fBstd::experimental::optional\fP< _Tp >::operator= (\fBnullopt_t\fP)\fC [inline]\fP, \fC [noexcept]\fP"

.PP
Definition at line \fB526\fP of file \fBexperimental/optional\fP\&.
.SS "template<typename _Tp > template<typename _Up > \fBenable_if_t\fP< __and_< __not_< \fBis_same\fP< _Tp, _Up > >, \fBis_constructible\fP< _Tp, _Up >, \fBis_assignable\fP< _Tp &, _Up >, __not_< __converts_from_optional< _Tp, _Up > >, __not_< __assigns_from_optional< _Tp, _Up > > >::value, \fBoptional\fP & > \fBstd::experimental::optional\fP< _Tp >::operator= (\fBoptional\fP< _Up > && __u)\fC [inline]\fP"

.PP
Definition at line \fB584\fP of file \fBexperimental/optional\fP\&.
.SS "template<typename _Tp > void \fBstd::experimental::optional\fP< _Tp >::swap (\fBoptional\fP< _Tp > & __other)\fC [inline]\fP, \fC [noexcept]\fP"

.PP
Definition at line \fB622\fP of file \fBexperimental/optional\fP\&.
.SS "template<typename _Tp > constexpr _Tp & \fBstd::experimental::optional\fP< _Tp >::value () &\fC [inline]\fP, \fC [constexpr]\fP"

.PP
Definition at line \fB680\fP of file \fBexperimental/optional\fP\&.
.SS "template<typename _Tp > constexpr _Tp && \fBstd::experimental::optional\fP< _Tp >::value () &&\fC [inline]\fP, \fC [constexpr]\fP"

.PP
Definition at line \fB689\fP of file \fBexperimental/optional\fP\&.
.SS "template<typename _Tp > constexpr const _Tp & \fBstd::experimental::optional\fP< _Tp >::value () const &\fC [inline]\fP, \fC [constexpr]\fP"

.PP
Definition at line \fB671\fP of file \fBexperimental/optional\fP\&.
.SS "template<typename _Tp > constexpr const _Tp && \fBstd::experimental::optional\fP< _Tp >::value () const &&\fC [inline]\fP, \fC [constexpr]\fP"

.PP
Definition at line \fB698\fP of file \fBexperimental/optional\fP\&.
.SS "template<typename _Tp > template<typename _Up > _Tp \fBstd::experimental::optional\fP< _Tp >::value_or (_Up && __u) &&\fC [inline]\fP"

.PP
Definition at line \fB722\fP of file \fBexperimental/optional\fP\&.
.SS "template<typename _Tp > template<typename _Up > constexpr _Tp \fBstd::experimental::optional\fP< _Tp >::value_or (_Up && __u) const &\fC [inline]\fP, \fC [constexpr]\fP"

.PP
Definition at line \fB708\fP of file \fBexperimental/optional\fP\&.

.SH "Author"
.PP 
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