1 //===----------------------------------------------------------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is dual licensed under the MIT and the University of Illinois Open
6 // Source Licenses. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 // UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
10
11 // <chrono>
12
13 // template<class Duration>
14 // using sys_time = time_point<system_clock, Duration>;
15 // using sys_seconds = sys_time<seconds>;
16 // using sys_days = sys_time<days>;
17
18 // [Example:
19 // sys_seconds{sys_days{1970y/January/1}}.time_since_epoch() is 0s.
20 // sys_seconds{sys_days{2000y/January/1}}.time_since_epoch() is 946’684’800s, which is 10’957 * 86’400s.
21 // —end example]
22
23
24 #include <chrono>
25 #include <cassert>
26
27 #include "test_macros.h"
28
main()29 int main()
30 {
31 using system_clock = std::chrono::system_clock;
32 using year = std::chrono::year;
33
34 using seconds = std::chrono::seconds;
35 using minutes = std::chrono::minutes;
36 using days = std::chrono::days;
37
38 using sys_seconds = std::chrono::sys_seconds;
39 using sys_minutes = std::chrono::sys_time<minutes>;
40 using sys_days = std::chrono::sys_days;
41
42 constexpr std::chrono::month January = std::chrono::January;
43
44 ASSERT_SAME_TYPE(std::chrono::sys_time<seconds>, sys_seconds);
45 ASSERT_SAME_TYPE(std::chrono::sys_time<days>, sys_days);
46
47 // Test the long form, too
48 ASSERT_SAME_TYPE(std::chrono::time_point<system_clock, seconds>, sys_seconds);
49 ASSERT_SAME_TYPE(std::chrono::time_point<system_clock, minutes>, sys_minutes);
50 ASSERT_SAME_TYPE(std::chrono::time_point<system_clock, days>, sys_days);
51
52 // Test some well known values
53 sys_days d0 = sys_days{year{1970}/January/1};
54 sys_days d1 = sys_days{year{2000}/January/1};
55 ASSERT_SAME_TYPE(decltype(d0.time_since_epoch()), days);
56 assert( d0.time_since_epoch().count() == 0);
57 assert( d1.time_since_epoch().count() == 10957);
58
59 sys_seconds s0{d0};
60 sys_seconds s1{d1};
61 ASSERT_SAME_TYPE(decltype(s0.time_since_epoch()), seconds);
62 assert( s0.time_since_epoch().count() == 0);
63 assert( s1.time_since_epoch().count() == 946684800L);
64 }
65