NAME

       std::_Optional_base< _Tp, bool, bool > - Class template that provides copy/move
       constructors of optional.

SYNOPSIS

       #include <optional>

       Inherits std::_Optional_base_impl< _Tp, _Dp >.

       Inherited by std::optional< _Inner_iter > [private],
       std::experimental::fundamentals_v1::optional< _Tp > [private], std::optional< _Tp >
       [private], and std::ranges::__detail::__non_propagating_cache< _Tp > [protected].

   Public Member Functions
       constexpr _Optional_base (_Optional_base &&__other)
           noexcept(is_nothrow_move_constructible_v< _Tp >)
       constexpr _Optional_base (const _Optional_base &__other)
       template<typename... _Args, enable_if_t< is_constructible_v< _Tp, _Args... >, bool >  =
           false> constexpr _Optional_base (in_place_t, _Args &&... __args)
       template<typename _Up , typename... _Args, enable_if_t< is_constructible_v< _Tp,
           initializer_list< _Up > &, _Args... >, bool >  = false> constexpr _Optional_base
           (in_place_t, initializer_list< _Up > __il, _Args &&... __args)
       _Optional_base & operator= (_Optional_base &&)=default
       _Optional_base & operator= (const _Optional_base &)=default

   Public Attributes
       _Optional_payload< _Tp > _M_payload

   Protected Types
       using _Stored_type = remove_const_t< _Tp >

   Protected Member Functions
       template<typename... _Args> constexpr void _M_construct (_Args &&... __args)
           noexcept(is_nothrow_constructible_v< _Stored_type, _Args... >)
       constexpr void _M_destruct () noexcept
       constexpr const _Tp & _M_get () const noexcept
       constexpr _Tp & _M_get () noexcept
       constexpr bool _M_is_engaged () const noexcept
       constexpr void _M_reset () noexcept

Detailed Description

   template<typename _Tp, bool = is_trivially_copy_constructible_v<_Tp>, bool =
       is_trivially_move_constructible_v<_Tp>>
       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.

       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.

       Whether the other special members are trivial is determined by the _Optional_payload<_Tp>
       specialization used for the _M_payload member.

       See also
           optional, _Enable_special_members

Author

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

                                            libstdc++std::_Optional_base< _Tp, bool, bool >(3cxx)