| // Copyright (C) 2019-2021 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-options "-std=gnu++2a" } |
| // { dg-do compile { target c++2a } } |
| |
| #include <functional> |
| |
| #ifndef __cpp_lib_constexpr_functional |
| # error "Feature test macro for constexpr invoke is missing" |
| #elif __cpp_lib_constexpr_functional < 201907L |
| # error "Feature test macro for constexpr invoke has wrong value" |
| #endif |
| |
| constexpr int inc(int i) { return i + 1; } |
| constexpr auto inc_f = &inc; |
| static_assert( std::invoke(inc_f, 2) == 3); |
| |
| struct Dec |
| { |
| constexpr int operator()(int i) const { return i - 1; } |
| }; |
| |
| static_assert( std::invoke(Dec{}, 5) == 4 ); |
