| 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 weekday; |
| 12 | |
| 13 | // constexpr weekday operator+(const days& x, const weekday& y) noexcept; |
| 14 | // Returns: weekday(int{x} + y.count()). |
| 15 | // |
| 16 | // constexpr weekday operator+(const weekday& x, const days& y) noexcept; |
| 17 | // Returns: |
| 18 | // weekday{modulo(static_cast<long long>(unsigned{x}) + y.count(), 7)} |
| 19 | // where modulo(n, 7) computes the remainder of n divided by 7 using Euclidean division. |
| 20 | // [Note: Given a divisor of 12, Euclidean division truncates towards negative infinity |
| 21 | // and always produces a remainder in the range of [0, 6]. |
| 22 | // Assuming no overflow in the signed summation, this operation results in a weekday |
| 23 | // holding a value in the range [0, 6] even if !x.ok(). -end note] |
| 24 | // [Example: Monday + days{6} == Sunday. -end example] |
| 25 | |
| 26 | #include <chrono> |
| 27 | #include <cassert> |
| 28 | #include <type_traits> |
| 29 | #include <utility> |
| 30 | |
| 31 | #include "test_macros.h" |
| 32 | #include "../../euclidian.h" |
| 33 | |
| 34 | using weekday = std::chrono::weekday; |
| 35 | using days = std::chrono::days; |
| 36 | |
| 37 | constexpr bool test() { |
| 38 | for (unsigned i = 0; i <= 6; ++i) |
| 39 | for (unsigned j = 0; j <= 6; ++j) { |
| 40 | weekday wd1 = weekday{i} + days{j}; |
| 41 | weekday wd2 = days{j} + weekday{i}; |
| 42 | assert(wd1 == wd2); |
| 43 | assert((wd1.c_encoding() == euclidian_addition<unsigned, 0, 6>(i, j))); |
| 44 | assert((wd2.c_encoding() == euclidian_addition<unsigned, 0, 6>(i, j))); |
| 45 | } |
| 46 | |
| 47 | // Check the example |
| 48 | assert(weekday{1} + days{6} == weekday{0}); |
| 49 | return true; |
| 50 | } |
| 51 | |
| 52 | int main(int, char**) { |
| 53 | ASSERT_NOEXCEPT(std::declval<weekday>() + std::declval<days>()); |
| 54 | ASSERT_SAME_TYPE(weekday, decltype(std::declval<weekday>() + std::declval<days>())); |
| 55 | |
| 56 | ASSERT_NOEXCEPT(std::declval<days>() + std::declval<weekday>()); |
| 57 | ASSERT_SAME_TYPE(weekday, decltype(std::declval<days>() + std::declval<weekday>())); |
| 58 | |
| 59 | test(); |
| 60 | static_assert(test()); |
| 61 | |
| 62 | return 0; |
| 63 | } |
| 64 | |