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++98, 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 //   precision is duration<common_type_t<Duration::rep, seconds::rep>,
19 //                                 ratio<1, 10^^fractional_width>>
20 
21 #include <chrono>
22 #include <cassert>
23 
24 #include "test_macros.h"
25 
26 constexpr unsigned long long powers[] = {
27 	1ULL,
28 	10ULL,
29 	100ULL,
30 	1000ULL,
31 	10000ULL,
32 	100000ULL,
33 	1000000ULL,
34 	10000000ULL,
35 	100000000ULL,
36 	1000000000ULL,
37 	10000000000ULL,
38 	100000000000ULL,
39 	1000000000000ULL,
40 	10000000000000ULL,
41 	100000000000000ULL,
42 	1000000000000000ULL,
43 	10000000000000000ULL,
44 	100000000000000000ULL,
45 	1000000000000000000ULL,
46 	10000000000000000000ULL
47 	};
48 
49 template <typename Duration, unsigned width>
check_precision()50 constexpr bool check_precision()
51 {
52 	using HMS = std::chrono::hh_mm_ss<Duration>;
53 	using CT  = std::common_type_t<typename Duration::rep, std::chrono::seconds::rep>;
54 	using Pre = std::chrono::duration<CT, std::ratio<1, powers[width]>>;
55 	return std::is_same_v<typename HMS::precision, Pre>;
56 }
57 
main(int,char **)58 int main(int, char**)
59 {
60 	using microfortnights = std::chrono::duration<int, std::ratio<756, 625>>;
61 
62 	static_assert( check_precision<std::chrono::hours,                               0>(), "");
63 	static_assert( check_precision<std::chrono::minutes,                             0>(), "");
64 	static_assert( check_precision<std::chrono::seconds,                             0>(), "");
65 	static_assert( check_precision<std::chrono::milliseconds,                        3>(), "");
66 	static_assert( check_precision<std::chrono::microseconds,                        6>(), "");
67 	static_assert( check_precision<std::chrono::nanoseconds,                         9>(), "");
68 	static_assert( check_precision<std::chrono::duration<int, std::ratio<  1,   2>>, 1>(), "");
69 	static_assert( check_precision<std::chrono::duration<int, std::ratio<  1,   3>>, 6>(), "");
70 	static_assert( check_precision<std::chrono::duration<int, std::ratio<  1,   4>>, 2>(), "");
71 	static_assert( check_precision<std::chrono::duration<int, std::ratio<  1,   5>>, 1>(), "");
72 	static_assert( check_precision<std::chrono::duration<int, std::ratio<  1,   6>>, 6>(), "");
73 	static_assert( check_precision<std::chrono::duration<int, std::ratio<  1,   7>>, 6>(), "");
74 	static_assert( check_precision<std::chrono::duration<int, std::ratio<  1,   8>>, 3>(), "");
75 	static_assert( check_precision<std::chrono::duration<int, std::ratio<  1,   9>>, 6>(), "");
76 	static_assert( check_precision<std::chrono::duration<int, std::ratio<  1,  10>>, 1>(), "");
77 	static_assert( check_precision<microfortnights,                                  4>(), "");
78 
79 	return 0;
80 }
81