164 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// REQUIRES: std-at-least-c++2010// UNSUPPORTED: no-filesystem, no-localization, no-tzdb11 12// XFAIL: libcpp-has-no-experimental-tzdb13// XFAIL: availability-tzdb-missing14 15// <chrono>16//17// class tai_clock;18 19// static utc_time<common_type_t<_Duration, seconds>>20// to_utc(const tai_time<_Duration>& __time) noexcept;21 22#include <chrono>23#include <cassert>24#include <source_location>25 26#include "test_macros.h"27#include "assert_macros.h"28#include "concat_macros.h"29 30static void test_known_values() {31 namespace cr = std::chrono;32 using namespace std::literals::chrono_literals;33 constexpr auto unix_to_tai_epoch_offset = cr::sys_days{cr::January / 1 / 1970} - cr::sys_days{cr::January / 1 / 1958};34 35 // [time.clock.tai.overview]/136 // ... 1958-01-01 00:00:00 TAI is equivalent to 1957-12-31 23:59:50 UTC37 // ... 2000-01-01 00:00:00 UTC is equivalent to 2000-01-01 00:00:32 TAI38 39 assert(cr::tai_clock::to_utc(cr::tai_seconds{0s}) ==40 cr::utc_clock::from_sys(cr::sys_days{cr::January / 1 / 1958} - 10s));41 42 assert(cr::tai_clock::to_utc(43 cr::tai_seconds{(cr::sys_days{cr::January / 1 / 2000} + unix_to_tai_epoch_offset).time_since_epoch()} +44 32s) == cr::utc_clock::from_sys(cr::sys_days{cr::January / 1 / 2000}));45}46 47template <class Duration>48static void test_leap_seconds(std::chrono::tai_time<Duration> tai,49 std::chrono::utc_time<Duration> expected,50 std::source_location loc = std::source_location::current()) {51 auto utc = std::chrono::tai_clock::to_utc(tai);52 TEST_REQUIRE(utc == expected,53 TEST_WRITE_CONCATENATED(loc, "\nExpected output ", expected, "\nActual output ", utc, '\n'));54}55 56// Tests set if existing database entries at the time of writing.57static void test_transitions() {58 using namespace std::literals::chrono_literals;59 namespace cr = std::chrono;60 61 // "sys" is the time of the transition to the next leap second.62 // "elapsed" is the number of leap seconds before the transition.63 auto test_transition = [](cr::sys_days sys, cr::seconds elapsed) {64 constexpr auto unix_to_tai_epoch_offset =65 cr::sys_days{cr::January / 1 / 1970} - cr::sys_days{cr::January / 1 / 1958};66 cr::tai_seconds tai{sys.time_since_epoch() + unix_to_tai_epoch_offset + elapsed};67 68 test_leap_seconds(tai - 1ns, cr::utc_clock::from_sys(sys - 1ns));69 test_leap_seconds(tai + 1s, cr::utc_clock::from_sys(sys));70 test_leap_seconds(tai + 1s + 1ns, cr::utc_clock::from_sys(sys + 1ns));71 };72 73 // Transitions from the start of UTC.74 test_transition(cr::sys_days{cr::July / 1 / 1972}, 10s);75 test_transition(cr::sys_days{cr::January / 1 / 1973}, 11s);76 test_transition(cr::sys_days{cr::January / 1 / 1974}, 12s);77 test_transition(cr::sys_days{cr::January / 1 / 1975}, 13s);78 test_transition(cr::sys_days{cr::January / 1 / 1976}, 14s);79 test_transition(cr::sys_days{cr::January / 1 / 1977}, 15s);80 test_transition(cr::sys_days{cr::January / 1 / 1978}, 16s);81 test_transition(cr::sys_days{cr::January / 1 / 1979}, 17s);82 test_transition(cr::sys_days{cr::January / 1 / 1980}, 18s);83 test_transition(cr::sys_days{cr::July / 1 / 1981}, 19s);84 test_transition(cr::sys_days{cr::July / 1 / 1982}, 20s);85 test_transition(cr::sys_days{cr::July / 1 / 1983}, 21s);86 test_transition(cr::sys_days{cr::July / 1 / 1985}, 22s);87 test_transition(cr::sys_days{cr::January / 1 / 1988}, 23s);88 test_transition(cr::sys_days{cr::January / 1 / 1990}, 24s);89 test_transition(cr::sys_days{cr::January / 1 / 1991}, 25s);90 test_transition(cr::sys_days{cr::July / 1 / 1992}, 26s);91 test_transition(cr::sys_days{cr::July / 1 / 1993}, 27s);92 test_transition(cr::sys_days{cr::July / 1 / 1994}, 28s);93 test_transition(cr::sys_days{cr::January / 1 / 1996}, 29s);94 test_transition(cr::sys_days{cr::July / 1 / 1997}, 30s);95 test_transition(cr::sys_days{cr::January / 1 / 1999}, 31s);96 test_transition(cr::sys_days{cr::January / 1 / 2006}, 32s);97 test_transition(cr::sys_days{cr::January / 1 / 2009}, 33s);98 test_transition(cr::sys_days{cr::July / 1 / 2012}, 34s);99 test_transition(cr::sys_days{cr::July / 1 / 2015}, 35s);100 test_transition(cr::sys_days{cr::January / 1 / 2017}, 36s);101}102 103// Tests whether the return type is the expected type.104static void test_return_type() {105 using namespace std::literals::chrono_literals;106 namespace cr = std::chrono;107 108 {109 [[maybe_unused]] std::same_as<cr::utc_time<cr::nanoseconds>> decltype(auto) _ =110 cr::tai_clock::to_utc(cr::tai_time<cr::nanoseconds>{0ns});111 }112 {113 [[maybe_unused]] std::same_as<cr::utc_time<cr::microseconds>> decltype(auto) _ =114 cr::tai_clock::to_utc(cr::tai_time<cr::microseconds>{0us});115 }116 {117 [[maybe_unused]] std::same_as<cr::utc_time<cr::milliseconds>> decltype(auto) _ =118 cr::tai_clock::to_utc(cr::tai_time<cr::milliseconds>{0ms});119 }120 121 {122 [[maybe_unused]] std::same_as<cr::utc_time<cr::seconds>> decltype(auto) _ =123 cr::tai_clock::to_utc(cr::tai_time<cr::seconds>{cr::seconds{0}});124 }125 126 {127 [[maybe_unused]] std::same_as<cr::utc_time<cr::seconds>> decltype(auto) _ =128 cr::tai_clock::to_utc(cr::tai_time<cr::minutes>{cr::minutes{0}});129 }130 {131 [[maybe_unused]] std::same_as<cr::utc_time<cr::seconds>> decltype(auto) _ =132 cr::tai_clock::to_utc(cr::tai_time<cr::hours>{cr::hours{0}});133 }134 {135 [[maybe_unused]] std::same_as<cr::utc_time<cr::seconds>> decltype(auto) _ =136 cr::tai_clock::to_utc(cr::tai_time<cr::days>{cr::days{0}});137 }138 {139 [[maybe_unused]] std::same_as<cr::utc_time<cr::seconds>> decltype(auto) _ =140 cr::tai_clock::to_utc(cr::tai_time<cr::weeks>{cr::weeks{0}});141 }142 {143 [[maybe_unused]] std::same_as<cr::utc_time<cr::seconds>> decltype(auto) _ =144 cr::tai_clock::to_utc(cr::tai_time<cr::months>{cr::months{0}});145 }146 {147 [[maybe_unused]] std::same_as<cr::utc_time<cr::seconds>> decltype(auto) _ =148 cr::tai_clock::to_utc(cr::tai_time<cr::years>{cr::years{0}});149 }150}151 152int main(int, const char**) {153 using namespace std::literals::chrono_literals;154 155 std::chrono::tai_seconds time = std::chrono::tai_seconds{0s};156 static_assert(noexcept(std::chrono::tai_clock::to_utc(time)));157 158 test_known_values();159 test_transitions();160 test_return_type();161 162 return 0;163}164