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// Copyright (C) 2019-2023 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 <concepts>
static_assert( std::swappable_with<int&, int&> );
static_assert( ! std::swappable_with<int, int> );
static_assert( ! std::swappable_with<int*, int*> );
static_assert( ! std::swappable_with<int&, const int&> );
static_assert( ! std::swappable_with<const int&, const int&> );
static_assert( ! std::swappable_with<int&, long&> );
namespace N1
{
struct Immovable
{
Immovable() = default;
Immovable(Immovable&&) = delete;
};
}
static_assert( ! std::swappable_with<N1::Immovable&, N1::Immovable&> );
namespace N2
{
struct Swappable
{
Swappable() = default;
Swappable(Swappable&&) = delete;
friend void swap(Swappable&, Swappable&) { }
};
}
static_assert( std::swappable_with<N2::Swappable&, N2::Swappable&> );
namespace N3
{
struct A { };
struct Proxy {
Proxy(A&) { }
friend void swap(Proxy, Proxy) { }
};
}
static_assert( std::swappable_with<N3::A&, N3::A&> );
static_assert( std::swappable_with<N3::A&, N3::Proxy> );
static_assert( std::swappable_with<N3::Proxy, N3::A&> );
static_assert( std::swappable_with<N3::Proxy, N3::Proxy> );
struct C { C(int&) { } };
void swap(int&, C&) { } // not symmetrical
static_assert( ! std::swappable_with<int, C> );
static_assert( ! std::swappable_with<C, int> );
struct D { D(int&) { } };
void swap(int&, D&) { }
void swap(D&&, int&) { } // only accepts rvalues
static_assert( ! std::swappable_with<int&, D> );
static_assert( ! std::swappable_with<D, int> );
struct E { E(int&) { } };
void swap(int, E&&) { } // only accepts rvalues
void swap(E&, int) { }
static_assert( ! std::swappable_with<int, E> );
static_assert( ! std::swappable_with<E, int> );
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