libcruft-util/concepts/clock.hpp

73 lines
2.1 KiB
C++

/*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*
* Copyright 2020, Danny Robson <danny@nerdcruft.net>
*/
#pragma once
#include "../concepts.hpp"
#include <chrono>
#include <ratio>
#include <cstdint>
namespace cruft::concepts {
namespace detail {
template <typename ValueT>
struct is_ratio : public std::false_type {};
template <std::intmax_t Num, std::intmax_t Denom>
struct is_ratio<
std::ratio<Num, Denom>
> : public std::true_type { };
};
template <typename T>
concept clock =
numeric<typename T::rep> &&
detail::is_ratio<typename T::period>::value &&
same_as<typename T::duration, std::chrono::duration<typename T::rep, typename T::period>> &&
//same_as<typename T::time_point, std::chrono::time_point<typename T::rep, typename T::period>> &&
same_as<decltype(T::is_steady), bool const> &&
requires (T t)
{
typename T::rep;
typename T::period;
typename T::time_point;
typename T::duration;
{ T::is_steady } -> convertible_to<bool>;
{ t.now () } -> same_as<typename T::time_point>;
};
namespace detail {
template <typename T>
concept trivial_clock_inner_type =
equality_comparable<T> &&
is_less_than_comparable_v<T> &&
default_constructible<T> &&
copy_constructible<T> &&
copy_assignable<T> &&
destructible<T> &&
numeric<T> &&
swappable<T>;
template <typename T>
concept trivial_clock =
trivial_clock_inner_type<typename T::rep> &&
trivial_clock_inner_type<typename T::duration> &&
trivial_clock_inner_type<typename T::time_point> &&
noexcept (std::declval<T> ().now());
}
template <typename T>
concept trivial_clock =
detail::trivial_clock<T> &&
detail::trivial_clock<typename T::time_point::clock>;
}