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// Copyright (C) 2019-2024 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING3. If not see
// <http://www.gnu.org/licenses/>.
// { dg-do compile { target c++20 } }
#include <functional>
// C++20 [func.identity]
static_assert( std::is_default_constructible_v<std::identity> );
static_assert( std::is_copy_constructible_v<std::identity> );
static_assert( std::is_move_constructible_v<std::identity> );
static_assert( std::is_copy_assignable_v<std::identity> );
static_assert( std::is_move_assignable_v<std::identity> );
static_assert( !std::is_invocable_v<std::identity> );
static_assert( !std::is_invocable_v<std::identity, int&, int&> );
static_assert( std::is_nothrow_invocable_r_v<int&, std::identity&, int&> );
static_assert( std::is_nothrow_invocable_r_v<const long&, std::identity, const long&> );
static_assert( std::is_nothrow_invocable_r_v<short&&, const std::identity&, short> );
static_assert( std::is_nothrow_invocable_r_v<const char&&, const std::identity, const char> );
int i;
static_assert( std::addressof(std::identity{}(i)) == std::addressof(i) );
using T = std::identity::is_transparent; // required typedef
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