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// Copyright (C) 2018-2019 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 } }
#include <functional>
// LWG 2993. reference_wrapper<T> conversion from T&&
static_assert(std::is_convertible<std::reference_wrapper<int>,
std::reference_wrapper<const int>>::value,
"LWG 2993 enables qualification conversions");
// The comments below are taken from the issue discussion and describe the
// behaviour before the resolution of LWG 2993. There should be no errors now.
struct convertible_from_int { convertible_from_int(int) { } };
void
test01()
{
void meow(std::reference_wrapper<int>); //#1
void meow(convertible_from_int); //#2
// error, ambiguous; would unambiguously call #2 if #1 instead took int&
meow(0);
}
void
test02()
{
std::reference_wrapper<int> purr();
// error, ambiguous: ICS exists from int prvalue to
// reference_wrapper<int> and from reference_wrapper<int> to int
auto x = true ? purr() : 0;
// error: no member 'type' because the conditional
// expression is ill-formed
using t = typename std::common_type<std::reference_wrapper<int>, int>::type;
}
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