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 month;
12
13// constexpr month& operator+=(const month& d) noexcept;
14// constexpr month& operator-=(const month& d) noexcept;
15
16#include <chrono>
17#include <cassert>
18#include <type_traits>
19#include <utility>
20
21#include "test_macros.h"
22
23constexpr bool test() {
24 using month = std::chrono::month;
25 using months = std::chrono::months;
26
27 for (unsigned i = 1; i <= 10; ++i) {
28 month m(i);
29 int exp = i + 10;
30 while (exp > 12)
31 exp -= 12;
32 assert(static_cast<unsigned>(m += months{10}) == static_cast<unsigned>(exp));
33 assert(static_cast<unsigned>(m) == static_cast<unsigned>(exp));
34 assert(m.ok());
35 }
36
37 for (unsigned i = 1; i <= 10; ++i) {
38 month m(i);
39 int exp = i - 9;
40 while (exp < 1)
41 exp += 12;
42 assert(static_cast<unsigned>(m -= months{9}) == static_cast<unsigned>(exp));
43 assert(static_cast<unsigned>(m) == static_cast<unsigned>(exp));
44 assert(m.ok());
45 }
46 return true;
47}
48
49int main(int, char**) {
50 using month = std::chrono::month;
51 using months = std::chrono::months;
52
53 ASSERT_NOEXCEPT(std::declval<month&>() += std::declval<months&>());
54 ASSERT_NOEXCEPT(std::declval<month&>() -= std::declval<months&>());
55 ASSERT_SAME_TYPE(month&, decltype(std::declval<month&>() += std::declval<months&>()));
56 ASSERT_SAME_TYPE(month&, decltype(std::declval<month&>() -= std::declval<months&>()));
57
58 test();
59 static_assert(test());
60
61 return 0;
62}
63

source code of libcxx/test/std/time/time.cal/time.cal.month/time.cal.month.members/plus_minus_equal.pass.cpp