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-exception
6//
7//===----------------------------------------------------------------------===//
8// UNSUPPORTED: c++03, c++11, c++14, c++17
9// <chrono>
10
11// template <class Duration>
12// class hh_mm_ss
13// {
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

source code of libcxx/test/std/time/time.hms/time.hms.members/width.pass.cpp