mirror of
https://github.com/autc04/Retro68.git
synced 2024-12-02 18:53:22 +00:00
43 lines
1.4 KiB
C++
43 lines
1.4 KiB
C++
// { dg-options "-std=gnu++17" }
|
|
|
|
// Copyright (C) 2016-2017 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/>.
|
|
|
|
#include <optional>
|
|
#include <testsuite_hooks.h>
|
|
|
|
class S{}; // No hash specialization
|
|
|
|
template<class T>
|
|
auto f(int) -> decltype(std::hash<std::optional<T>>(), std::true_type());
|
|
|
|
template<class T>
|
|
auto f(...) -> decltype(std::false_type());
|
|
|
|
static_assert(!decltype(f<S>(0))::value, "");
|
|
static_assert(!std::is_invocable_v<
|
|
std::hash<std::optional<S>>&, std::optional<S> const&> );
|
|
static_assert(std::is_invocable_v<
|
|
std::hash<std::optional<int>>&, std::optional<int> const&> );
|
|
|
|
int main()
|
|
{
|
|
int x = 42;
|
|
std::optional<int> x2 = 42;
|
|
VERIFY(std::hash<int>()(x) == std::hash<std::optional<int>>()(x2));
|
|
}
|