| // Copyright (C) 2016-2026 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++11 } } |
| |
| // NB: Don't include any other headers in this file. |
| // LWG 2192 requires <cmath> to declare overloads for integral types. |
| #include <cmath> |
| |
| template<typename, typename> struct is_same { enum { value = 0 }; }; |
| template<typename T> struct is_same<T, T> { enum { value = 1 }; }; |
| |
| template<typename T, typename U = T> |
| constexpr bool check(T val) { |
| return is_same<decltype(std::abs(val)), U>::value; |
| } |
| |
| // Unsigned arguments that promote to int are valid: |
| static_assert( check<short, int>(1), "abs((short)1) returns int" ); |
| static_assert( check<unsigned short, int>(1), |
| "abs((unsigned short)1) returns int" ); |
| |
| static_assert( check(1), "abs(1) returns int" ); |
| static_assert( check(1l), "abs(1l) returns long" ); |
| static_assert( check(1ll), "abs(1ll) returns long long" ); |
