85 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 year_month_weekday;12 13// constexpr operator sys_days() const noexcept;14//15// Returns: If y_.ok() && m_.ok() && wdi_.weekday().ok(), returns a16// sys_days that represents the date (index() - 1) * 7 days after the first17// weekday() of year()/month(). If index() is 0 the returned sys_days18// represents the date 7 days prior to the first weekday() of19// year()/month(). Otherwise the returned value is unspecified.20//21 22#include <chrono>23#include <cassert>24#include <type_traits>25#include <utility>26 27#include "test_macros.h"28 29int main(int, char**)30{31 using year = std::chrono::year;32 using month = std::chrono::month;33 using weekday_indexed = std::chrono::weekday_indexed;34 using sys_days = std::chrono::sys_days;35 using days = std::chrono::days;36 using year_month_weekday = std::chrono::year_month_weekday;37 38 ASSERT_NOEXCEPT(sys_days(std::declval<year_month_weekday>()));39 40 {41 constexpr year_month_weekday ymwd{year{1970}, month{1}, weekday_indexed{std::chrono::Thursday, 1}};42 constexpr sys_days sd{ymwd};43 44 static_assert( sd.time_since_epoch() == days{0}, "");45 static_assert( year_month_weekday{sd} == ymwd, ""); // and back46 }47 48 {49 constexpr year_month_weekday ymwd{year{2000}, month{2}, weekday_indexed{std::chrono::Wednesday, 1}};50 constexpr sys_days sd{ymwd};51 52 static_assert( sd.time_since_epoch() == days{10957+32}, "");53 static_assert( year_month_weekday{sd} == ymwd, ""); // and back54 }55 56 // There's one more leap day between 1/1/40 and 1/1/7057 // when compared to 1/1/70 -> 1/1/200058 {59 constexpr year_month_weekday ymwd{year{1940}, month{1},weekday_indexed{std::chrono::Tuesday, 1}};60 constexpr sys_days sd{ymwd};61 62 static_assert( sd.time_since_epoch() == days{-10957}, "");63 static_assert( year_month_weekday{sd} == ymwd, ""); // and back64 }65 66 {67 year_month_weekday ymwd{year{1939}, month{11}, weekday_indexed{std::chrono::Wednesday, 5}};68 sys_days sd{ymwd};69 70 assert( sd.time_since_epoch() == days{-(10957+34)});71 assert( year_month_weekday{sd} == ymwd); // and back72 }73 74 {75 // Index 0 returns 7 weekdays before index 1 and can't be round-tripped.76 constexpr year_month_weekday ymwd{year{2000}, month{2}, weekday_indexed{std::chrono::Wednesday, 0}};77 constexpr sys_days sd{ymwd};78 79 static_assert(sd.time_since_epoch() == days{10957 + 25});80 static_assert(year_month_weekday{sd} != ymwd); // and back fails81 }82 83 return 0;84}85