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
10 // <chrono>
11 // class year_month;
12
13 // constexpr year_month operator-(const year_month& ym, const years& dy) noexcept;
14 // Returns: ym + -dy.
15 //
16 // constexpr year_month operator-(const year_month& ym, const months& dm) noexcept;
17 // Returns: ym + -dm.
18 //
19 // constexpr months operator-(const year_month& x, const year_month& y) noexcept;
20 // Returns: x.year() - y.year() + months{static_cast<int>(unsigned{x.month()}) -
21 // static_cast<int>(unsigned{y.month()})}
22
23
24 #include <chrono>
25 #include <type_traits>
26 #include <cassert>
27
28 #include "test_macros.h"
29
main(int,char **)30 int main(int, char**)
31 {
32 using year = std::chrono::year;
33 using years = std::chrono::years;
34 using month = std::chrono::month;
35 using months = std::chrono::months;
36 using year_month = std::chrono::year_month;
37
38 { // year_month - years
39 ASSERT_NOEXCEPT( std::declval<year_month>() - std::declval<years>());
40 ASSERT_SAME_TYPE(year_month, decltype(std::declval<year_month>() - std::declval<years>()));
41
42 // static_assert(testConstexprYears (year_month{year{1}, month{1}}), "");
43
44 year_month ym{year{1234}, std::chrono::January};
45 for (int i = 0; i <= 10; ++i)
46 {
47 year_month ym1 = ym - years{i};
48 assert(static_cast<int>(ym1.year()) == 1234 - i);
49 assert(ym1.month() == std::chrono::January);
50 }
51 }
52
53 { // year_month - months
54 ASSERT_NOEXCEPT( std::declval<year_month>() - std::declval<months>());
55 ASSERT_SAME_TYPE(year_month, decltype(std::declval<year_month>() - std::declval<months>()));
56
57 // static_assert(testConstexprMonths(year_month{year{1}, month{1}}), "");
58
59 year_month ym{year{1234}, std::chrono::November};
60 for (int i = 0; i <= 10; ++i) // TODO test wrap-around
61 {
62 year_month ym1 = ym - months{i};
63 assert(static_cast<int>(ym1.year()) == 1234);
64 assert(ym1.month() == month(11 - i));
65 }
66 }
67
68 { // year_month - year_month
69 ASSERT_NOEXCEPT( std::declval<year_month>() - std::declval<year_month>());
70 ASSERT_SAME_TYPE(months, decltype(std::declval<year_month>() - std::declval<year_month>()));
71
72 // static_assert(testConstexprMonths(year_month{year{1}, month{1}}), "");
73
74 // Same year
75 year y{2345};
76 for (int i = 1; i <= 12; ++i)
77 for (int j = 1; j <= 12; ++j)
78 {
79 months diff = year_month{y, month(i)} - year_month{y, month(j)};
80 assert(diff.count() == i - j);
81 }
82
83 // TODO: different year
84
85 }
86
87 return 0;
88 }
89