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 // class year_month_weekday;
13 
14 // constexpr operator sys_days() const noexcept;
15 //
16 // Returns: If y_.ok() && m_.ok() && wdi_.weekday().ok(), returns a
17 //    sys_days that represents the date (index() - 1) * 7 days after the first
18 //    weekday() of year()/month(). If index() is 0 the returned sys_days
19 //    represents the date 7 days prior to the first weekday() of
20 //    year()/month(). Otherwise the returned value is unspecified.
21 //
22 
23 #include <chrono>
24 #include <type_traits>
25 #include <cassert>
26 
27 #include "test_macros.h"
28 
main()29 int main()
30 {
31     using year               = std::chrono::year;
32     using month              = std::chrono::month;
33     using weekday_indexed    = std::chrono::weekday_indexed;
34     using sys_days           = std::chrono::sys_days;
35     using days               = std::chrono::days;
36     using year_month_weekday = std::chrono::year_month_weekday;
37 
38     ASSERT_NOEXCEPT(sys_days(std::declval<year_month_weekday>()));
39 
40     {
41     constexpr year_month_weekday ymwd{year{1970}, month{1}, weekday_indexed{std::chrono::Thursday, 1}};
42     constexpr sys_days sd{ymwd};
43 
44     static_assert( sd.time_since_epoch() == days{0}, "");
45     static_assert( year_month_weekday{sd} == ymwd, ""); // and back
46     }
47 
48     {
49     constexpr year_month_weekday ymwd{year{2000}, month{2}, weekday_indexed{std::chrono::Wednesday, 1}};
50     constexpr sys_days sd{ymwd};
51 
52     static_assert( sd.time_since_epoch() == days{10957+32}, "");
53     static_assert( year_month_weekday{sd} == ymwd, ""); // and back
54     }
55 
56 //  There's one more leap day between 1/1/40 and 1/1/70
57 //  when compared to 1/1/70 -> 1/1/2000
58     {
59     constexpr year_month_weekday ymwd{year{1940}, month{1},weekday_indexed{std::chrono::Tuesday, 1}};
60     constexpr sys_days sd{ymwd};
61 
62     static_assert( sd.time_since_epoch() == days{-10957}, "");
63     static_assert( year_month_weekday{sd} == ymwd, ""); // and back
64     }
65 
66     {
67     year_month_weekday ymwd{year{1939}, month{11}, weekday_indexed{std::chrono::Wednesday, 5}};
68     sys_days sd{ymwd};
69 
70     assert( sd.time_since_epoch() == days{-(10957+34)});
71     assert( year_month_weekday{sd} == ymwd); // and back
72     }
73 
74 }
75