53 lines · cpp
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-exception6//7//===----------------------------------------------------------------------===//8// UNSUPPORTED: c++03, c++11, c++14, c++179 10// <chrono>11// class day;12 13// constexpr day operator-(const day& x, const days& y) noexcept;14// Returns: x + -y.15//16// constexpr days operator-(const day& x, const day& y) noexcept;17// Returns: days{int(unsigned{x}) - int(unsigned{y}).18 19#include <chrono>20#include <cassert>21#include <type_traits>22#include <utility>23 24#include "test_macros.h"25 26using day = std::chrono::day;27using days = std::chrono::days;28 29constexpr bool test() {30 day dy{12};31 for (unsigned i = 0; i <= 10; ++i) {32 day d1 = dy - days{i};33 days off = dy - day{i};34 assert(static_cast<unsigned>(d1) == 12 - i);35 assert(off.count() == static_cast<int>(12 - i)); // days is signed36 }37 38 return true;39}40 41int main(int, char**) {42 ASSERT_NOEXCEPT(std::declval<day>() - std::declval<days>());43 ASSERT_NOEXCEPT(std::declval<day>() - std::declval<day>());44 45 ASSERT_SAME_TYPE(day, decltype(std::declval<day>() - std::declval<days>()));46 ASSERT_SAME_TYPE(days, decltype(std::declval<day>() - std::declval<day>()));47 48 test();49 static_assert(test());50 51 return 0;52}53