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#include <chrono>
24#include <cassert>
25#include <type_traits>
26#include <utility>
27
28#include "test_macros.h"
29
30using year = std::chrono::year;
31using years = std::chrono::years;
32using month = std::chrono::month;
33using months = std::chrono::months;
34using year_month = std::chrono::year_month;
35
36constexpr bool test() {
37 { // year_month - years
38
39 year_month ym{year{1234}, std::chrono::January};
40 for (int i = 0; i <= 10; ++i) {
41 year_month ym1 = ym - years{i};
42 assert(static_cast<int>(ym1.year()) == 1234 - i);
43 assert(ym1.month() == std::chrono::January);
44 }
45 }
46
47 { // year_month - months
48
49 year_month ym{year{1234}, std::chrono::November};
50 for (int i = 0; i <= 10; ++i) {
51 year_month ym1 = ym - months{i};
52 assert(static_cast<int>(ym1.year()) == 1234);
53 assert(ym1.month() == month(11 - i));
54 }
55 // Test the year wraps around.
56 for (int i = 12; i <= 15; ++i) {
57 year_month ym1 = ym - months{i};
58 assert(static_cast<int>(ym1.year()) == 1233);
59 assert(ym1.month() == month(11 - i + 12));
60 }
61 }
62
63 { // year_month - year_month
64
65 // Same year
66 year y{2345};
67 for (int i = 1; i <= 12; ++i)
68 for (int j = 1; j <= 12; ++j) {
69 months diff = year_month{y, month(i)} - year_month{y, month(j)};
70 assert(diff.count() == i - j);
71 }
72
73 // TODO: different year
74 }
75 return true;
76}
77
78int main(int, char**) {
79 // year_month - years
80 ASSERT_NOEXCEPT(std::declval<year_month>() - std::declval<years>());
81 ASSERT_SAME_TYPE(year_month, decltype(std::declval<year_month>() - std::declval<years>()));
82
83 // year_month - months
84 ASSERT_NOEXCEPT(std::declval<year_month>() - std::declval<months>());
85 ASSERT_SAME_TYPE(year_month, decltype(std::declval<year_month>() - std::declval<months>()));
86
87 // year_month - year_month
88 ASSERT_NOEXCEPT(std::declval<year_month>() - std::declval<year_month>());
89 ASSERT_SAME_TYPE(months, decltype(std::declval<year_month>() - std::declval<year_month>()));
90
91 test();
92 static_assert(test());
93
94 return 0;
95}
96

source code of libcxx/test/std/time/time.cal/time.cal.ym/time.cal.ym.nonmembers/minus.pass.cpp