162 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 tai_time<common_type_t<_Duration, seconds>>20// from_utc(const utc<_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::from_utc(cr::utc_clock::from_sys(cr::sys_days{cr::January / 1 / 1958} - 10s)) ==40 cr::tai_seconds{0s});41 42 assert(cr::tai_clock::from_utc(cr::utc_clock::from_sys(cr::sys_days{cr::January / 1 / 2000})) ==43 cr::tai_seconds{(cr::sys_days{cr::January / 1 / 2000} + unix_to_tai_epoch_offset).time_since_epoch()} + 32s);44}45 46template <class Duration>47static void test_leap_seconds(std::chrono::utc_time<Duration> utc,48 std::chrono::tai_time<Duration> expected,49 std::source_location loc = std::source_location::current()) {50 auto tai = std::chrono::tai_clock::from_utc(utc);51 TEST_REQUIRE(tai == expected,52 TEST_WRITE_CONCATENATED(loc, "\nExpected output ", expected, "\nActual output ", tai, '\n'));53}54 55// Tests set if existing database entries at the time of writing.56static void test_transitions() {57 using namespace std::literals::chrono_literals;58 namespace cr = std::chrono;59 60 // "sys" is the time of the transition to the next leap second.61 // "elapsed" is the number of leap seconds before the transition.62 auto test_transition = [](cr::sys_days sys, cr::seconds elapsed) {63 constexpr auto unix_to_tai_epoch_offset =64 cr::sys_days{cr::January / 1 / 1970} - cr::sys_days{cr::January / 1 / 1958};65 cr::tai_seconds tai{sys.time_since_epoch() + unix_to_tai_epoch_offset + elapsed};66 67 test_leap_seconds(cr::utc_clock::from_sys(sys - 1ns), tai - 1ns);68 test_leap_seconds(cr::utc_clock::from_sys(sys), tai + 1s);69 test_leap_seconds(cr::utc_clock::from_sys(sys) + 1ns, tai + 1s + 1ns);70 };71 72 // Transitions from the start of UTC.73 test_transition(cr::sys_days{cr::July / 1 / 1972}, 10s);74 test_transition(cr::sys_days{cr::January / 1 / 1973}, 11s);75 test_transition(cr::sys_days{cr::January / 1 / 1974}, 12s);76 test_transition(cr::sys_days{cr::January / 1 / 1975}, 13s);77 test_transition(cr::sys_days{cr::January / 1 / 1976}, 14s);78 test_transition(cr::sys_days{cr::January / 1 / 1977}, 15s);79 test_transition(cr::sys_days{cr::January / 1 / 1978}, 16s);80 test_transition(cr::sys_days{cr::January / 1 / 1979}, 17s);81 test_transition(cr::sys_days{cr::January / 1 / 1980}, 18s);82 test_transition(cr::sys_days{cr::July / 1 / 1981}, 19s);83 test_transition(cr::sys_days{cr::July / 1 / 1982}, 20s);84 test_transition(cr::sys_days{cr::July / 1 / 1983}, 21s);85 test_transition(cr::sys_days{cr::July / 1 / 1985}, 22s);86 test_transition(cr::sys_days{cr::January / 1 / 1988}, 23s);87 test_transition(cr::sys_days{cr::January / 1 / 1990}, 24s);88 test_transition(cr::sys_days{cr::January / 1 / 1991}, 25s);89 test_transition(cr::sys_days{cr::July / 1 / 1992}, 26s);90 test_transition(cr::sys_days{cr::July / 1 / 1993}, 27s);91 test_transition(cr::sys_days{cr::July / 1 / 1994}, 28s);92 test_transition(cr::sys_days{cr::January / 1 / 1996}, 29s);93 test_transition(cr::sys_days{cr::July / 1 / 1997}, 30s);94 test_transition(cr::sys_days{cr::January / 1 / 1999}, 31s);95 test_transition(cr::sys_days{cr::January / 1 / 2006}, 32s);96 test_transition(cr::sys_days{cr::January / 1 / 2009}, 33s);97 test_transition(cr::sys_days{cr::July / 1 / 2012}, 34s);98 test_transition(cr::sys_days{cr::July / 1 / 2015}, 35s);99 test_transition(cr::sys_days{cr::January / 1 / 2017}, 36s);100}101 102// Tests whether the return type is the expected type.103static void test_return_type() {104 using namespace std::literals::chrono_literals;105 namespace cr = std::chrono;106 107 {108 [[maybe_unused]] std::same_as<cr::tai_time<cr::nanoseconds>> decltype(auto) _ =109 cr::tai_clock::from_utc(cr::utc_time<cr::nanoseconds>{0ns});110 }111 {112 [[maybe_unused]] std::same_as<cr::tai_time<cr::microseconds>> decltype(auto) _ =113 cr::tai_clock::from_utc(cr::utc_time<cr::microseconds>{0us});114 }115 {116 [[maybe_unused]] std::same_as<cr::tai_time<cr::milliseconds>> decltype(auto) _ =117 cr::tai_clock::from_utc(cr::utc_time<cr::milliseconds>{0ms});118 }119 120 {121 [[maybe_unused]] std::same_as<cr::tai_time<cr::seconds>> decltype(auto) _ =122 cr::tai_clock::from_utc(cr::utc_time<cr::seconds>{cr::seconds{0}});123 }124 125 {126 [[maybe_unused]] std::same_as<cr::tai_time<cr::seconds>> decltype(auto) _ =127 cr::tai_clock::from_utc(cr::utc_time<cr::minutes>{cr::minutes{0}});128 }129 {130 [[maybe_unused]] std::same_as<cr::tai_time<cr::seconds>> decltype(auto) _ =131 cr::tai_clock::from_utc(cr::utc_time<cr::hours>{cr::hours{0}});132 }133 {134 [[maybe_unused]] std::same_as<cr::tai_time<cr::seconds>> decltype(auto) _ =135 cr::tai_clock::from_utc(cr::utc_time<cr::days>{cr::days{0}});136 }137 {138 [[maybe_unused]] std::same_as<cr::tai_time<cr::seconds>> decltype(auto) _ =139 cr::tai_clock::from_utc(cr::utc_time<cr::weeks>{cr::weeks{0}});140 }141 {142 [[maybe_unused]] std::same_as<cr::tai_time<cr::seconds>> decltype(auto) _ =143 cr::tai_clock::from_utc(cr::utc_time<cr::months>{cr::months{0}});144 }145 {146 [[maybe_unused]] std::same_as<cr::tai_time<cr::seconds>> decltype(auto) _ =147 cr::tai_clock::from_utc(cr::utc_time<cr::years>{cr::years{0}});148 }149}150 151int main(int, const char**) {152 using namespace std::literals::chrono_literals;153 std::chrono::utc_seconds time = std::chrono::utc_seconds{0s};154 static_assert(noexcept(std::chrono::tai_clock::from_utc(time)));155 156 test_known_values();157 test_transitions();158 test_return_type();159 160 return 0;161}162