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 
30 template <typename Duration, unsigned width>
31 constexpr bool check_width()
32 {
33 	using HMS = std::chrono::hh_mm_ss<Duration>;
34 	return HMS::fractional_width == width;
35 }
36 
37 int 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