.TH "std::_Optional_base< _Tp, bool, bool >" 3cxx "Thu Feb 16 2023" "libstdc++" \" -*- nroff -*-
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.SH NAME
std::_Optional_base< _Tp, bool, bool > \- Class template that provides copy/move constructors of optional\&.  

.SH SYNOPSIS
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.PP
.PP
Inherits std::_Optional_base_impl< _Tp, _Dp >\&.
.PP
Inherited by \fBstd::experimental::fundamentals_v1::optional< _Tp >\fP\fC [private]\fP, and \fBstd::optional< _Tp >\fP\fC [private]\fP\&.
.SS "Public Member Functions"

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.RI "constexpr \fB_Optional_base\fP (\fB_Optional_base\fP &&__other) noexcept(is_nothrow_move_constructible_v< _Tp >)"
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.RI "constexpr \fB_Optional_base\fP (const \fB_Optional_base\fP &__other)"
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.RI "template<typename\&.\&.\&. _Args, \fBenable_if_t\fP< is_constructible_v< _Tp, _Args\&.\&.\&. >, bool >  = false> constexpr \fB_Optional_base\fP (in_place_t, _Args &&\&.\&.\&. __args)"
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.RI "template<typename _Up , typename\&.\&.\&. _Args, \fBenable_if_t\fP< is_constructible_v< _Tp, \fBinitializer_list\fP< _Up > &, _Args\&.\&.\&. >, bool >  = false> constexpr \fB_Optional_base\fP (in_place_t, \fBinitializer_list\fP< _Up > __il, _Args &&\&.\&.\&. __args)"
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.RI "\fB_Optional_base\fP & \fBoperator=\fP (\fB_Optional_base\fP &&)=default"
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.RI "\fB_Optional_base\fP & \fBoperator=\fP (const \fB_Optional_base\fP &)=default"
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.SS "Public Attributes"

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.RI "_Optional_payload< _Tp > \fB_M_payload\fP"
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.SS "Protected Types"

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.RI "using \fB_Stored_type\fP = \fBremove_const_t\fP< _Tp >"
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.SS "Protected Member Functions"

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.RI "template<typename\&.\&.\&. _Args> constexpr void \fB_M_construct\fP (_Args &&\&.\&.\&. __args) noexcept(is_nothrow_constructible_v< _Stored_type, _Args\&.\&.\&. >)"
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.RI "constexpr void \fB_M_destruct\fP () noexcept"
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.RI "constexpr const _Tp & \fB_M_get\fP () const noexcept"
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.RI "constexpr _Tp & \fB_M_get\fP () noexcept"
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.RI "constexpr bool \fB_M_is_engaged\fP () const noexcept"
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.RI "constexpr void \fB_M_reset\fP () noexcept"
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.SH "Detailed Description"
.PP 

.SS "template<typename _Tp, bool = is_trivially_copy_constructible_v<_Tp>, bool = is_trivially_move_constructible_v<_Tp>>
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struct std::_Optional_base< _Tp, bool, bool >"Class template that provides copy/move constructors of optional\&. 

Such a separate base class template is necessary in order to conditionally make copy/move constructors trivial\&.
.PP
When the contained value is trivially copy/move constructible, the copy/move constructors of _Optional_base will invoke the trivial copy/move constructor of _Optional_payload\&. Otherwise, they will invoke _Optional_payload(bool, const _Optional_payload&) or _Optional_payload(bool, _Optional_payload&&) to initialize the contained value, if copying/moving an engaged optional\&.
.PP
Whether the other special members are trivial is determined by the _Optional_payload<_Tp> specialization used for the _M_payload member\&.
.PP
\fBSee also\fP
.RS 4
optional, _Enable_special_members 
.RE
.PP

.PP
Definition at line \fB472\fP of file \fBoptional\fP\&.
.SH "Member Typedef Documentation"
.PP 
.SS "template<typename _Tp , typename _Dp > using std::_Optional_base_impl< _Tp, _Dp >::_Stored_type =  \fBremove_const_t\fP<_Tp>\fC [protected]\fP, \fC [inherited]\fP"

.PP
Definition at line \fB410\fP of file \fBoptional\fP\&.
.SH "Constructor & Destructor Documentation"
.PP 
.SS "template<typename _Tp , bool  = is_trivially_copy_constructible_v<_Tp>, bool  = is_trivially_move_constructible_v<_Tp>> template<typename\&.\&.\&. _Args, \fBenable_if_t\fP< is_constructible_v< _Tp, _Args\&.\&.\&. >, bool >  = false> constexpr \fBstd::_Optional_base\fP< _Tp, bool, bool >::_Optional_base (in_place_t, _Args &&\&.\&.\&. __args)\fC [inline]\fP, \fC [explicit]\fP, \fC [constexpr]\fP"

.PP
Definition at line \fB482\fP of file \fBoptional\fP\&.
.SS "template<typename _Tp , bool  = is_trivially_copy_constructible_v<_Tp>, bool  = is_trivially_move_constructible_v<_Tp>> template<typename _Up , typename\&.\&.\&. _Args, \fBenable_if_t\fP< is_constructible_v< _Tp, \fBinitializer_list\fP< _Up > &, _Args\&.\&.\&. >, bool >  = false> constexpr \fBstd::_Optional_base\fP< _Tp, bool, bool >::_Optional_base (in_place_t, \fBinitializer_list\fP< _Up > __il, _Args &&\&.\&.\&. __args)\fC [inline]\fP, \fC [explicit]\fP, \fC [constexpr]\fP"

.PP
Definition at line \fB491\fP of file \fBoptional\fP\&.
.SS "template<typename _Tp , bool  = is_trivially_copy_constructible_v<_Tp>, bool  = is_trivially_move_constructible_v<_Tp>> constexpr \fBstd::_Optional_base\fP< _Tp, bool, bool >::_Optional_base (const \fB_Optional_base\fP< _Tp, bool, bool > & __other)\fC [inline]\fP, \fC [constexpr]\fP"

.PP
Definition at line \fB499\fP of file \fBoptional\fP\&.
.SS "template<typename _Tp , bool  = is_trivially_copy_constructible_v<_Tp>, bool  = is_trivially_move_constructible_v<_Tp>> constexpr \fBstd::_Optional_base\fP< _Tp, bool, bool >::_Optional_base (\fB_Optional_base\fP< _Tp, bool, bool > && __other)\fC [inline]\fP, \fC [constexpr]\fP, \fC [noexcept]\fP"

.PP
Definition at line \fB504\fP of file \fBoptional\fP\&.
.SH "Member Function Documentation"
.PP 
.SS "template<typename _Tp , typename _Dp > template<typename\&.\&.\&. _Args> constexpr void std::_Optional_base_impl< _Tp, _Dp >::_M_construct (_Args &&\&.\&.\&. __args)\fC [inline]\fP, \fC [constexpr]\fP, \fC [protected]\fP, \fC [noexcept]\fP, \fC [inherited]\fP"

.PP
Definition at line \fB416\fP of file \fBoptional\fP\&.
.SS "template<typename _Tp , typename _Dp > constexpr void std::_Optional_base_impl< _Tp, _Dp >::_M_destruct ()\fC [inline]\fP, \fC [constexpr]\fP, \fC [protected]\fP, \fC [noexcept]\fP, \fC [inherited]\fP"

.PP
Definition at line \fB424\fP of file \fBoptional\fP\&.
.SS "template<typename _Tp , typename _Dp > constexpr const _Tp & std::_Optional_base_impl< _Tp, _Dp >::_M_get () const\fC [inline]\fP, \fC [constexpr]\fP, \fC [protected]\fP, \fC [noexcept]\fP, \fC [inherited]\fP"

.PP
Definition at line \fB444\fP of file \fBoptional\fP\&.
.SS "template<typename _Tp , typename _Dp > constexpr _Tp & std::_Optional_base_impl< _Tp, _Dp >::_M_get ()\fC [inline]\fP, \fC [constexpr]\fP, \fC [protected]\fP, \fC [noexcept]\fP, \fC [inherited]\fP"

.PP
Definition at line \fB437\fP of file \fBoptional\fP\&.
.SS "template<typename _Tp , typename _Dp > constexpr bool std::_Optional_base_impl< _Tp, _Dp >::_M_is_engaged () const\fC [inline]\fP, \fC [constexpr]\fP, \fC [protected]\fP, \fC [noexcept]\fP, \fC [inherited]\fP"

.PP
Definition at line \fB432\fP of file \fBoptional\fP\&.
.SS "template<typename _Tp , typename _Dp > constexpr void std::_Optional_base_impl< _Tp, _Dp >::_M_reset ()\fC [inline]\fP, \fC [constexpr]\fP, \fC [protected]\fP, \fC [noexcept]\fP, \fC [inherited]\fP"

.PP
Definition at line \fB429\fP of file \fBoptional\fP\&.
.SH "Member Data Documentation"
.PP 
.SS "template<typename _Tp , bool  = is_trivially_copy_constructible_v<_Tp>, bool  = is_trivially_move_constructible_v<_Tp>> _Optional_payload<_Tp> \fBstd::_Optional_base\fP< _Tp, bool, bool >::_M_payload"

.PP
Definition at line \fB514\fP of file \fBoptional\fP\&.

.SH "Author"
.PP 
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