161 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 9// UNSUPPORTED: c++03, c++11, c++14, c++1710// UNSUPPORTED: no-filesystem, no-localization, no-tzdb11 12// XFAIL: libcpp-has-no-experimental-tzdb13// XFAIL: availability-tzdb-missing14 15// <chrono>16 17// class time_zone;18 19// template <class _Duration>20// sys_time<common_type_t<Duration, seconds>>21// to_sys(const local_time<Duration>& tp, choose z) const;22 23#include <chrono>24#include <format>25#include <cassert>26#include <string_view>27 28#include "test_macros.h"29 30// Tests unique conversions. To make sure the test is does not depend on changes31// in the database it uses a time zone with a fixed offset.32static void test_unique() {33 using namespace std::literals::chrono_literals;34 35 const std::chrono::time_zone* tz = std::chrono::locate_zone("Etc/GMT+1");36 37 assert(tz->to_sys(std::chrono::local_time<std::chrono::nanoseconds>{-1ns}, std::chrono::choose::earliest) ==38 std::chrono::sys_time<std::chrono::nanoseconds>{-1ns + 1h});39 40 assert(tz->to_sys(std::chrono::local_time<std::chrono::microseconds>{0us}, std::chrono::choose::latest) ==41 std::chrono::sys_time<std::chrono::microseconds>{1h});42 43 assert(tz->to_sys(44 std::chrono::local_time<std::chrono::seconds>{45 (std::chrono::sys_days{std::chrono::January / 1 / -21970}).time_since_epoch()},46 std::chrono::choose::earliest) ==47 std::chrono::sys_time<std::chrono::seconds>{48 (std::chrono::sys_days{std::chrono::January / 1 / -21970}).time_since_epoch() + 1h});49 50 // sys_time<common_type_t<Duration, seconds>> is seconds for the larger types51 assert(tz->to_sys(52 std::chrono::local_time<std::chrono::days>{53 (std::chrono::sys_days{std::chrono::January / 1 / 21970}).time_since_epoch()},54 std::chrono::choose::latest) ==55 std::chrono::sys_time<std::chrono::seconds>{56 (std::chrono::sys_days{std::chrono::January / 1 / 21970}).time_since_epoch() + 1h});57 58 assert(tz->to_sys(std::chrono::local_time<std::chrono::weeks>{}, std::chrono::choose::earliest) ==59 std::chrono::sys_time<std::chrono::seconds>{60 (std::chrono::sys_days{std::chrono::January / 1 / 1970}).time_since_epoch() + 1h});61 62 // Note months and years cannot be streamed; however these functions don't63 // throw an exception and thus can be used.64 assert(tz->to_sys(std::chrono::local_time<std::chrono::months>{}, std::chrono::choose::latest) ==65 std::chrono::sys_time<std::chrono::seconds>{66 (std::chrono::sys_days{std::chrono::January / 1 / 1970}).time_since_epoch() + 1h});67 68 assert(tz->to_sys(std::chrono::local_time<std::chrono::years>{}, std::chrono::choose::earliest) ==69 std::chrono::sys_time<std::chrono::seconds>{70 (std::chrono::sys_days{std::chrono::January / 1 / 1970}).time_since_epoch() + 1h});71}72 73// Tests non-existant conversions.74static void test_nonexistent() {75 using namespace std::literals::chrono_literals;76 77 const std::chrono::time_zone* tz = std::chrono::locate_zone("Europe/Berlin");78 79 // Z Europe/Berlin 0:53:28 - LMT 1893 Ap80 // ...81 // 1 DE CE%sT 198082 // 1 E CE%sT83 //84 // ...85 // R E 1981 ma - Mar lastSu 1u 1 S86 // R E 1996 ma - O lastSu 1u 0 -87 88 // Pick an historic date where it's well known what the time zone rules were.89 // This makes it unlikely updates to the database change these rules.90 std::chrono::local_time<std::chrono::seconds> time{91 (std::chrono::sys_days{std::chrono::March / 30 / 1986} + 2h).time_since_epoch()};92 93 std::chrono::sys_seconds expected{time.time_since_epoch() - 1h};94 95 // Validates whether the database did not change.96 std::chrono::local_info info = tz->get_info(time);97 assert(info.result == std::chrono::local_info::nonexistent);98 99 assert(tz->to_sys(time + 0ns, std::chrono::choose::earliest) == expected);100 assert(tz->to_sys(time + 0us, std::chrono::choose::latest) == expected);101 assert(tz->to_sys(time + 0ms, std::chrono::choose::earliest) == expected);102 assert(tz->to_sys(time + 0s, std::chrono::choose::latest) == expected);103 104 // The entire nonexisting hour should map to the same time.105 // For nonexistant the value of std::chrono::choose has no effect.106 assert(tz->to_sys(time + 1s, std::chrono::choose::earliest) == expected);107 assert(tz->to_sys(time + 1min, std::chrono::choose::latest) == expected);108 assert(tz->to_sys(time + 30min, std::chrono::choose::earliest) == expected);109 assert(tz->to_sys(time + 59min + 59s, std::chrono::choose::latest) == expected);110}111 112// Tests ambiguous conversions.113static void test_ambiguous() {114 using namespace std::literals::chrono_literals;115 116 const std::chrono::time_zone* tz = std::chrono::locate_zone("Europe/Berlin");117 118 // Z Europe/Berlin 0:53:28 - LMT 1893 Ap119 // ...120 // 1 DE CE%sT 1980121 // 1 E CE%sT122 //123 // ...124 // R E 1981 ma - Mar lastSu 1u 1 S125 // R E 1996 ma - O lastSu 1u 0 -126 127 // Pick an historic date where it's well known what the time zone rules were.128 // This makes it unlikely updates to the database change these rules.129 std::chrono::local_time<std::chrono::seconds> time{130 (std::chrono::sys_days{std::chrono::September / 28 / 1986} + 2h).time_since_epoch()};131 132 std::chrono::sys_seconds earlier{time.time_since_epoch() - 2h};133 std::chrono::sys_seconds later{time.time_since_epoch() - 1h};134 135 // Validates whether the database did not change.136 std::chrono::local_info info = tz->get_info(time);137 assert(info.result == std::chrono::local_info::ambiguous);138 139 assert(tz->to_sys(time + 0ns, std::chrono::choose::earliest) == earlier);140 assert(tz->to_sys(time + 0us, std::chrono::choose::latest) == later);141 assert(tz->to_sys(time + 0ms, std::chrono::choose::earliest) == earlier);142 assert(tz->to_sys(time + 0s, std::chrono::choose::latest) == later);143 144 // Test times in the ambiguous hour145 assert(tz->to_sys(time + 1s, std::chrono::choose::earliest) == earlier + 1s);146 assert(tz->to_sys(time + 1min, std::chrono::choose::latest) == later + 1min);147 assert(tz->to_sys(time + 30min, std::chrono::choose::earliest) == earlier + 30min);148 assert(tz->to_sys(time + 59min + 59s, std::chrono::choose::latest) == later + 59min + 59s);149}150 151// This test does the basic validations of this function. The library function152// uses `local_info get_info(const local_time<Duration>& tp)` as implementation153// detail. The get_info function does extensive testing of the data.154int main(int, char**) {155 test_unique();156 test_nonexistent();157 test_ambiguous();158 159 return 0;160}161