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// { dg-do compile { target c++17 } }
// Copyright (C) 2013-2022 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>
int main()
{
// [20.5.6] Disengaged state indicator
static_assert( std::is_same<decltype(std::nullopt), const std::nullopt_t>(), "" );
static_assert( std::is_empty<std::nullopt_t>(), "" );
static_assert( __is_literal_type(std::nullopt_t), "" );
static_assert( !std::is_default_constructible<std::nullopt_t>(), "" );
{
constexpr std::optional<int> o = std::nullopt;
static_assert( !o, "" );
}
{
constexpr std::optional<int> o = { std::nullopt };
static_assert( !o, "" );
}
{
constexpr std::optional<int> o { std::nullopt };
static_assert( !o, "" );
}
}
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