PR libstdc++/81468 constrain std::chrono::time_point constructor

[thirdparty/gcc.git] / libstdc++-v3 / testsuite / 20_util / time_point / cons / 81468.cc

// Copyright (C) 2017 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 <chrono>
#include <type_traits>

using namespace std;
using namespace std::chrono;

template <class Duration>
    using sys_time = time_point<system_clock, Duration>;

static_assert(is_constructible<sys_time<milliseconds>, sys_time<seconds>>{},
    "Can construct time_point from one with lower precision duration");

// PR libstdc++/81468 - DR 1177
static_assert(!is_constructible<sys_time<seconds>, sys_time<milliseconds>>{},
    "Cannot construct time_point from one with higher precision duration");