std::identity - [func.identity] The identity function.

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

                                                    libstdc++                                std::identity(3cxx)

       [func.identity] The identity function.

       std::identity - [func.identity] The identity function.

       #include <functional>

   PublicTypesusingis_transparent = __is_transparentPublicMemberFunctions
       template<typename _Tp > constexpr _Tp && operator() (_Tp &&__t) const noexcept