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// { dg-options "-std=gnu++11" }
// { dg-do compile }
// Copyright (C) 2012-2015 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>
#include <chrono>
// Helper types:
struct has_type_impl
{
template<typename T, typename = typename T::type>
static std::true_type test(int);
template<typename>
static std::false_type test(...);
};
template<typename T>
struct has_type : public decltype(has_type_impl::test<T>(0))
{};
template<typename T, typename Expected>
struct is_expected_type : public std::is_same<typename T::type, Expected>
{};
template<typename P1, typename P2>
struct and_ : public std::conditional<P1::value, P2, std::false_type>::type
{};
template<typename T, typename Expected>
struct is_type : public and_<has_type<T>, is_expected_type<T, Expected>>
{};
// Inspection types:
typedef std::chrono::duration<int, std::nano> din;
typedef std::chrono::duration<double, std::nano> ddn;
typedef std::chrono::duration<int, std::milli> dim;
static_assert(is_type<std::common_type<din, din>, din>(), "");
static_assert(is_type<std::common_type<din, din, din>, din>(), "");
static_assert(is_type<std::common_type<din, ddn>, ddn>(), "");
static_assert(is_type<std::common_type<din, din, ddn>, ddn>(), "");
static_assert(is_type<std::common_type<din, ddn>, ddn>(), "");
static_assert(is_type<std::common_type<ddn, din, din>, ddn>(), "");
static_assert(!has_type<std::common_type<din, int>>(), "");
static_assert(!has_type<std::common_type<din, din, int>>(), "");
static_assert(!has_type<std::common_type<int, din, din>>(), "");
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