.TH "std::experimental::optional< _Tp >" 3cxx "libstdc++" \" -*- nroff -*- .ad l .nh .SH NAME std::experimental::optional< _Tp > \- Class template for optional values\&. .SH SYNOPSIS .br .PP .PP \fC#include \fP .PP Inherits _Optional_base< _Tp >, and \fBstd::_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 > >\fP\&. .SS "Public Types" .in +1c .ti -1c .RI "\fBusing\fP \fBvalue_type\fP = _Tp" .br .in -1c .SS "Public Member Functions" .in +1c .ti -1c .RI "template<\fBtypename\fP \fB_Up\fP = _Tp, \fBenable_if_t\fP< __and_< __not_< \fBis_same\fP< \fBoptional\fP< _Tp >, \fBdecay_t\fP< \fB_Up\fP > > >, \fBis_constructible\fP< _Tp, \fB_Up\fP && >, \fBis_convertible\fP< \fB_Up\fP &&, _Tp > >::value, bool > = true> \fBconstexpr\fP \fBoptional\fP (\fB_Up\fP &&__t)" .br .ti -1c .RI "template<\fBtypename\fP \fB_Up\fP = _Tp, \fBenable_if_t\fP< __and_< __not_< \fBis_same\fP< \fBoptional\fP< _Tp >, \fBdecay_t\fP< \fB_Up\fP > > >, \fBis_constructible\fP< _Tp, \fB_Up\fP && >, __not_< \fBis_convertible\fP< \fB_Up\fP &&, _Tp > > >::value, bool > = false> \fBconstexpr\fP \fBoptional\fP (\fB_Up\fP &&__t)" .br .ti -1c .RI "template<\fBtypename\fP \fB_Up\fP , \fBenable_if_t\fP< __and_< __not_< \fBis_same\fP< _Tp, \fB_Up\fP > >, \fBis_constructible\fP< _Tp, \fBconst\fP \fB_Up\fP & >, \fBis_convertible\fP< \fBconst\fP \fB_Up\fP &, _Tp >, __not_< \fB__converts_from_optional\fP< _Tp, \fB_Up\fP > > >::value, bool > = true> \fBconstexpr\fP \fBoptional\fP (\fBconst\fP \fBoptional\fP< \fB_Up\fP > &__t)" .br .ti -1c .RI "template<\fBtypename\fP \fB_Up\fP , \fBenable_if_t\fP< __and_< __not_< \fBis_same\fP< _Tp, \fB_Up\fP > >, \fBis_constructible\fP< _Tp, \fBconst\fP \fB_Up\fP & >, __not_< \fBis_convertible\fP< \fBconst\fP \fB_Up\fP &, _Tp > >, __not_< \fB__converts_from_optional\fP< _Tp, \fB_Up\fP > > >::value, bool > = false> \fBconstexpr\fP \fBoptional\fP (\fBconst\fP \fBoptional\fP< \fB_Up\fP > &__t)" .br .ti -1c .RI "template<\fBtypename\fP \fB_Up\fP , \fBenable_if_t\fP< __and_< __not_< \fBis_same\fP< _Tp, \fB_Up\fP > >, \fBis_constructible\fP< _Tp, \fB_Up\fP && >, \fBis_convertible\fP< \fB_Up\fP &&, _Tp >, __not_< \fB__converts_from_optional\fP< _Tp, \fB_Up\fP > > >::value, bool > = true> \fBconstexpr\fP \fBoptional\fP (\fBoptional\fP< \fB_Up\fP > &&__t)" .br .ti -1c .RI "template<\fBtypename\fP \fB_Up\fP , \fBenable_if_t\fP< __and_< __not_< \fBis_same\fP< _Tp, \fB_Up\fP > >, \fBis_constructible\fP< _Tp, \fB_Up\fP && >, __not_< \fBis_convertible\fP< \fB_Up\fP &&, _Tp > >, __not_< \fB__converts_from_optional\fP< _Tp, \fB_Up\fP > > >::value, bool > = false> \fBconstexpr\fP \fBoptional\fP (\fBoptional\fP< \fB_Up\fP > &&__t)" .br .ti -1c .RI "template \fBenable_if_t\fP< \fBis_constructible\fP< _Tp, \fB_Args\fP &&\&.\&.\&. >::value > \fBemplace\fP (\fB_Args\fP &&\&.\&.\&. \fB__args\fP)" .br .ti -1c .RI "template<\fBtypename\fP \fB_Up\fP , typename\&.\&.\&. _Args> \fBenable_if_t\fP< \fBis_constructible\fP< _Tp, \fBinitializer_list\fP< \fB_Up\fP > &, \fB_Args\fP &&\&.\&.\&. >::value > \fBemplace\fP (\fBinitializer_list\fP< \fB_Up\fP > \fB__il\fP, \fB_Args\fP &&\&.\&.\&. \fB__args\fP)" .br .ti -1c .RI "\fBconstexpr\fP \fBoperator bool\fP () \fBconst\fP \fBnoexcept\fP" .br .ti -1c .RI "\fBconstexpr\fP _Tp & \fBoperator*\fP () &" .br .ti -1c .RI "\fBconstexpr\fP _Tp && \fBoperator*\fP () &&" .br .ti -1c .RI "\fBconstexpr\fP \fBconst\fP _Tp & \fBoperator*\fP () \fBconst\fP &" .br .ti -1c .RI "\fBconstexpr\fP \fBconst\fP _Tp && \fBoperator*\fP () \fBconst\fP &&" .br .ti -1c .RI "_Tp * \fBoperator\->\fP ()" .br .ti -1c .RI "\fBconstexpr\fP \fBconst\fP _Tp * \fBoperator\->\fP () \fBconst\fP" .br .ti -1c .RI "template<\fBtypename\fP \fB_Up\fP = _Tp> \fBenable_if_t\fP< __and_< __not_< \fBis_same\fP< \fBoptional\fP< _Tp >, \fBdecay_t\fP< \fB_Up\fP > > >, \fBis_constructible\fP< _Tp, \fB_Up\fP >, __not_< __and_< \fBis_scalar\fP< _Tp >, \fBis_same\fP< _Tp, \fBdecay_t\fP< \fB_Up\fP > > > >, \fBis_assignable\fP< _Tp &, \fB_Up\fP > >::value, \fBoptional\fP & > \fBoperator=\fP (\fB_Up\fP &&\fB__u\fP)" .br .ti -1c .RI "template<\fBtypename\fP \fB_Up\fP > \fBenable_if_t\fP< __and_< __not_< \fBis_same\fP< _Tp, \fB_Up\fP > >, \fBis_constructible\fP< _Tp, \fBconst\fP \fB_Up\fP & >, \fBis_assignable\fP< _Tp &, \fB_Up\fP >, __not_< \fB__converts_from_optional\fP< _Tp, \fB_Up\fP > >, __not_< \fB__assigns_from_optional\fP< _Tp, \fB_Up\fP > > >::value, \fBoptional\fP & > \fBoperator=\fP (\fBconst\fP \fBoptional\fP< \fB_Up\fP > &\fB__u\fP)" .br .ti -1c .RI "\fBoptional\fP & \fBoperator=\fP (\fBnullopt_t\fP) \fBnoexcept\fP" .br .ti -1c .RI "template<\fBtypename\fP \fB_Up\fP > \fBenable_if_t\fP< __and_< __not_< \fBis_same\fP< _Tp, \fB_Up\fP > >, \fBis_constructible\fP< _Tp, \fB_Up\fP >, \fBis_assignable\fP< _Tp &, \fB_Up\fP >, __not_< \fB__converts_from_optional\fP< _Tp, \fB_Up\fP > >, __not_< \fB__assigns_from_optional\fP< _Tp, \fB_Up\fP > > >::value, \fBoptional\fP & > \fBoperator=\fP (\fBoptional\fP< \fB_Up\fP > &&\fB__u\fP)" .br .ti -1c .RI "\fBvoid\fP \fBswap\fP (\fBoptional\fP &__other) \fBnoexcept\fP(\fBis_nothrow_move_constructible\fP< _Tp >() &&__is_nothrow_swappable< _Tp >::value)" .br .ti -1c .RI "\fBconstexpr\fP _Tp & \fBvalue\fP () &" .br .ti -1c .RI "\fBconstexpr\fP _Tp && \fBvalue\fP () &&" .br .ti -1c .RI "\fBconstexpr\fP \fBconst\fP _Tp & \fBvalue\fP () \fBconst\fP &" .br .ti -1c .RI "\fBconstexpr\fP \fBconst\fP _Tp && \fBvalue\fP () \fBconst\fP &&" .br .ti -1c .RI "template<\fBtypename\fP \fB_Up\fP > _Tp \fBvalue_or\fP (\fB_Up\fP &&\fB__u\fP) &&" .br .ti -1c .RI "template<\fBtypename\fP \fB_Up\fP > \fBconstexpr\fP _Tp \fBvalue_or\fP (\fB_Up\fP &&\fB__u\fP) \fBconst\fP &" .br .in -1c .SH "Detailed Description" .PP .SS "template<\fBtypename\fP _Tp> .br class std::experimental::optional< _Tp >"Class template for optional values\&. .SH "Author" .PP Generated automatically by Doxygen for libstdc++ from the source code\&.