60 lines · cpp
1//===----------------------------------------------------------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8// UNSUPPORTED: c++03, c++11, c++14, c++179// <chrono>10 11// template <class Duration>12// class hh_mm_ss13// {14// public:15// static unsigned constexpr fractional_width = see below;16// using precision = see below;17//18// fractional_width is the number of fractional decimal digits represented by precision.19// fractional_width has the value of the smallest possible integer in the range [0, 18]20// such that precision will exactly represent all values of Duration.21// If no such value of fractional_width exists, then fractional_width is 6.22 23 24#include <chrono>25#include <cassert>26#include <ratio>27 28#include "test_macros.h"29 30template <typename Duration, unsigned width>31constexpr bool check_width()32{33 using HMS = std::chrono::hh_mm_ss<Duration>;34 return HMS::fractional_width == width;35}36 37int main(int, char**)38{39 using microfortnights = std::chrono::duration<int, std::ratio<756, 625>>;40 41 static_assert( check_width<std::chrono::hours, 0>(), "");42 static_assert( check_width<std::chrono::minutes, 0>(), "");43 static_assert( check_width<std::chrono::seconds, 0>(), "");44 static_assert( check_width<std::chrono::milliseconds, 3>(), "");45 static_assert( check_width<std::chrono::microseconds, 6>(), "");46 static_assert( check_width<std::chrono::nanoseconds, 9>(), "");47 static_assert( check_width<std::chrono::duration<int, std::ratio< 1, 2>>, 1>(), "");48 static_assert( check_width<std::chrono::duration<int, std::ratio< 1, 3>>, 6>(), "");49 static_assert( check_width<std::chrono::duration<int, std::ratio< 1, 4>>, 2>(), "");50 static_assert( check_width<std::chrono::duration<int, std::ratio< 1, 5>>, 1>(), "");51 static_assert( check_width<std::chrono::duration<int, std::ratio< 1, 6>>, 6>(), "");52 static_assert( check_width<std::chrono::duration<int, std::ratio< 1, 7>>, 6>(), "");53 static_assert( check_width<std::chrono::duration<int, std::ratio< 1, 8>>, 3>(), "");54 static_assert( check_width<std::chrono::duration<int, std::ratio< 1, 9>>, 6>(), "");55 static_assert( check_width<std::chrono::duration<int, std::ratio< 1, 10>>, 1>(), "");56 static_assert( check_width<microfortnights, 4>(), "");57 58 return 0;59}60