compat-chrono.h 1.67 KB
/* Copyright (C) 2019
 *
 * This file is part of the osdev components suite
 *
 * This program 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 2, or (at your option) any
 * later version.
 *
 * This program 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 program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA
 */
#include <chrono>
#include <type_traits>

// function std::chrono::ceil is added in the c++17 standard.
// Added implementation from https://en.cppreference.com/w/cpp/chrono/duration/ceil
// to this compatibility header. The header only defines this implementation when
// the c++ compiler is used with an older standard.

#if !defined __cpp_lib_chrono || __cpp_lib_chrono < 201611

namespace std {
namespace chrono {

template <class T>
struct is_duration : std::false_type
{
};
template <class Rep, class Period>
struct is_duration<
    std::chrono::duration<Rep, Period>> : std::true_type
{
};

template <class To, class Rep, class Period,
    class = typename enable_if<is_duration<To>{}>::type>
To ceil(const std::chrono::duration<Rep, Period>& d)
{
    To t = std::chrono::duration_cast<To>(d);
    if (t < d)
        return t + To{ 1 };
    return t;
}

}       // End namespace chrono
}       // End namespace std

#endif