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// { dg-options "-std=gnu++17" }
// { dg-do run { target c++17 } }
// Copyright (C) 2013-2020 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>
struct exception {};
int counter = 0;
struct mixin_counter
{
mixin_counter() { ++counter; }
mixin_counter(mixin_counter const&) { ++counter; }
~mixin_counter() { --counter; }
};
namespace ns
{
struct value_type : private mixin_counter
{
explicit value_type(int state) : state(state) { }
int state;
};
int swaps = 0;
void
swap(value_type& lhs, value_type& rhs)
{
++swaps;
using std::swap;
swap(lhs.state, rhs.state);
}
} // namespace ns
int main()
{
using O = std::optional<ns::value_type>;
VERIFY( ns::swaps == 0 );
{
O o, p;
swap(o, p);
VERIFY( !o );
VERIFY( !p );
}
{
O o { std::in_place, 45 }, p;
swap(o, p);
VERIFY( !o );
VERIFY( p && p->state == 45 );
}
{
O o, p { std::in_place, 45 };
swap(o, p);
VERIFY( o && o->state == 45 );
VERIFY( !p );
}
{
O o { std::in_place, 167 }, p { std::in_place, 999 };
VERIFY( ns::swaps == 0 );
swap(o, p);
VERIFY( o && o->state == 999 );
VERIFY( p && p->state == 167 );
VERIFY( ns::swaps == 1 );
}
VERIFY( counter == 0 );
}
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