libstdc++-v3/testsuite/20_util/is_constructible/51185.cc

// { dg-do compile { target c++11 } }

// Copyright (C) 2011-2021 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 <type_traits>

struct A { };
struct B : A {
#if __cpp_aggregate_bases && __cpp_aggregate_paren_init
  // A user-declared constructor prevents B from being an aggregate.
  // Otherwise 'B&& b{A{}};' becomes valid in C++17 (__cpp_aggregate_bases),
  // and 'B&& b(A{});' becomes valid in C++17 (__cpp_aggregate_paren_init).
  B();
#endif
};

// libstdc++/51185
void f()
{
  static_assert(!std::is_constructible<B &&, A>(), "");
  static_assert(!std::is_constructible<B const &&, A>(), "");
  static_assert(!std::is_constructible<B const &&, A const>(), "");
  static_assert(!std::is_constructible<B volatile &&, A>(), "");
  static_assert(!std::is_constructible<B volatile &&, A volatile>(), "");
  static_assert(!std::is_constructible<B const volatile &&, A>(), "");
  static_assert(!std::is_constructible<B const volatile &&, A const>(), "");
  static_assert(!std::is_constructible<B const volatile &&, A volatile>(), "");
  static_assert(!std::is_constructible<B const volatile &&,
		A const volatile>(), "");
}