40 lines
1.3 KiB
C++
40 lines
1.3 KiB
C++
// 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 } }
|
|
// { dg-add-options no_pch }
|
|
|
|
#include <utility>
|
|
|
|
#ifndef __cpp_lib_constexpr_algorithms
|
|
# error "Feature test macro for constexpr std::exchange is missing in <utility>"
|
|
#elif __cpp_lib_constexpr_algorithms < 201806L
|
|
# error "Feature test macro for constexpr std::exchange has wrong value in <utility>"
|
|
#endif
|
|
|
|
constexpr bool
|
|
test()
|
|
{
|
|
constexpr double e_v = 2.71828182846;
|
|
double e = e_v;
|
|
constexpr double pi_v = 3.14159265359;
|
|
const auto x = std::exchange(e, pi_v);
|
|
|
|
return x == e_v && e == pi_v;
|
|
}
|
|
|
|
static_assert(test());
|