// { dg-options "-std=gnu++17" }
// { dg-do run { target c++17 }  }

// Copyright (C) 2013-2019 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/>.

#include <optional>
#include <testsuite_hooks.h>

#include <tuple>
#include <string>

namespace ns
{
  struct value_type
  {
    int i;
    std::string s;
  };

  bool
  operator==(value_type const& lhs, value_type const& rhs)
  { return std::tie(lhs.i, lhs.s) == std::tie(rhs.i, rhs.s); }

  bool
  operator<(value_type const& lhs, value_type const& rhs)
  { return std::tie(lhs.i, lhs.s) < std::tie(rhs.i, rhs.s); }

} // namespace ns

int main()
{
  using ns::value_type;
  using O = std::optional<value_type>;
  using std::nullopt;

  {
    O o;
    VERIFY( o == nullopt );
    VERIFY( nullopt == o );
    VERIFY( !(o != nullopt) );
    VERIFY( !(nullopt != o) );
  }

  {
    O o { std::in_place };
    VERIFY( !(o == nullopt) );
    VERIFY( !(nullopt == o) );
    VERIFY( o != nullopt );
    VERIFY( nullopt != o );
  }
}