| // -*- C++ -*- |
| //===----------------------------------------------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef _LIBCPP___CHRONO_CONVERT_TO_TM_H |
| #define _LIBCPP___CHRONO_CONVERT_TO_TM_H |
| |
| #include <__chrono/calendar.h> |
| #include <__chrono/concepts.h> |
| #include <__chrono/day.h> |
| #include <__chrono/duration.h> |
| #include <__chrono/file_clock.h> |
| #include <__chrono/hh_mm_ss.h> |
| #include <__chrono/month.h> |
| #include <__chrono/month_weekday.h> |
| #include <__chrono/monthday.h> |
| #include <__chrono/statically_widen.h> |
| #include <__chrono/system_clock.h> |
| #include <__chrono/time_point.h> |
| #include <__chrono/weekday.h> |
| #include <__chrono/year.h> |
| #include <__chrono/year_month.h> |
| #include <__chrono/year_month_day.h> |
| #include <__chrono/year_month_weekday.h> |
| #include <__concepts/same_as.h> |
| #include <__config> |
| #include <__format/format_error.h> |
| #include <__memory/addressof.h> |
| #include <__type_traits/is_convertible.h> |
| #include <cstdint> |
| #include <ctime> |
| #include <limits> |
| |
| #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) |
| # pragma GCC system_header |
| #endif |
| |
| _LIBCPP_PUSH_MACROS |
| #include <__undef_macros> |
| |
| _LIBCPP_BEGIN_NAMESPACE_STD |
| |
| #if _LIBCPP_STD_VER >= 20 |
| |
| // Conerts a chrono date and weekday to a given _Tm type. |
| // |
| // This is an implementation detail for the function |
| // template <class _Tm, class _ChronoT> |
| // _Tm __convert_to_tm(const _ChronoT& __value) |
| // |
| // This manually converts the two values to the proper type. It is possible to |
| // convert from sys_days to time_t and then to _Tm. But this leads to the Y2K |
| // bug when time_t is a 32-bit signed integer. Chrono considers years beyond |
| // the year 2038 valid, so instead do the transformation manually. |
| template <class _Tm, class _Date> |
| requires(same_as<_Date, chrono::year_month_day> || same_as<_Date, chrono::year_month_day_last>) |
| _LIBCPP_HIDE_FROM_ABI _Tm __convert_to_tm(const _Date& __date, chrono::weekday __weekday) { |
| _Tm __result = {}; |
| # ifdef __GLIBC__ |
| __result.tm_zone = "UTC"; |
| # endif |
| __result.tm_year = static_cast<int>(__date.year()) - 1900; |
| __result.tm_mon = static_cast<unsigned>(__date.month()) - 1; |
| __result.tm_mday = static_cast<unsigned>(__date.day()); |
| __result.tm_wday = static_cast<unsigned>(__weekday.c_encoding()); |
| __result.tm_yday = |
| (static_cast<chrono::sys_days>(__date) - |
| static_cast<chrono::sys_days>(chrono::year_month_day{__date.year(), chrono::January, chrono::day{1}})) |
| .count(); |
| |
| return __result; |
| } |
| |
| template <class _Tm, class _Duration> |
| _LIBCPP_HIDE_FROM_ABI _Tm __convert_to_tm(const chrono::sys_time<_Duration> __tp) { |
| chrono::sys_days __days = chrono::floor<chrono::days>(__tp); |
| chrono::year_month_day __ymd{__days}; |
| |
| _Tm __result = std::__convert_to_tm<_Tm>(chrono::year_month_day{__ymd}, chrono::weekday{__days}); |
| |
| uint64_t __sec = |
| chrono::duration_cast<chrono::seconds>(__tp - chrono::time_point_cast<chrono::seconds>(__days)).count(); |
| __sec %= 24 * 3600; |
| __result.tm_hour = __sec / 3600; |
| __sec %= 3600; |
| __result.tm_min = __sec / 60; |
| __result.tm_sec = __sec % 60; |
| |
| return __result; |
| } |
| |
| // Convert a chrono (calendar) time point, or dururation to the given _Tm type, |
| // which must have the same properties as std::tm. |
| template <class _Tm, class _ChronoT> |
| _LIBCPP_HIDE_FROM_ABI _Tm __convert_to_tm(const _ChronoT& __value) { |
| _Tm __result = {}; |
| # ifdef __GLIBC__ |
| __result.tm_zone = "UTC"; |
| # endif |
| |
| if constexpr (__is_time_point<_ChronoT>) { |
| if constexpr (same_as<typename _ChronoT::clock, chrono::system_clock>) |
| return std::__convert_to_tm<_Tm>(__value); |
| else if constexpr (same_as<typename _ChronoT::clock, chrono::file_clock>) |
| return std::__convert_to_tm<_Tm>(_ChronoT::clock::to_sys(__value)); |
| else if constexpr (same_as<typename _ChronoT::clock, chrono::local_t>) |
| return std::__convert_to_tm<_Tm>(chrono::sys_time<typename _ChronoT::duration>{__value.time_since_epoch()}); |
| else |
| static_assert(sizeof(_ChronoT) == 0, "TODO: Add the missing clock specialization"); |
| } else if constexpr (chrono::__is_duration<_ChronoT>::value) { |
| // [time.format]/6 |
| // ... However, if a flag refers to a "time of day" (e.g. %H, %I, %p, |
| // etc.), then a specialization of duration is interpreted as the time of |
| // day elapsed since midnight. |
| |
| // Not all values can be converted to hours, it may run into ratio |
| // conversion errors. In that case the conversion to seconds works. |
| if constexpr (is_convertible_v<_ChronoT, chrono::hours>) { |
| auto __hour = chrono::floor<chrono::hours>(__value); |
| auto __sec = chrono::duration_cast<chrono::seconds>(__value - __hour); |
| __result.tm_hour = __hour.count() % 24; |
| __result.tm_min = __sec.count() / 60; |
| __result.tm_sec = __sec.count() % 60; |
| } else { |
| uint64_t __sec = chrono::duration_cast<chrono::seconds>(__value).count(); |
| __sec %= 24 * 3600; |
| __result.tm_hour = __sec / 3600; |
| __sec %= 3600; |
| __result.tm_min = __sec / 60; |
| __result.tm_sec = __sec % 60; |
| } |
| } else if constexpr (same_as<_ChronoT, chrono::day>) |
| __result.tm_mday = static_cast<unsigned>(__value); |
| else if constexpr (same_as<_ChronoT, chrono::month>) |
| __result.tm_mon = static_cast<unsigned>(__value) - 1; |
| else if constexpr (same_as<_ChronoT, chrono::year>) |
| __result.tm_year = static_cast<int>(__value) - 1900; |
| else if constexpr (same_as<_ChronoT, chrono::weekday>) |
| __result.tm_wday = __value.c_encoding(); |
| else if constexpr (same_as<_ChronoT, chrono::weekday_indexed> || same_as<_ChronoT, chrono::weekday_last>) |
| __result.tm_wday = __value.weekday().c_encoding(); |
| else if constexpr (same_as<_ChronoT, chrono::month_day>) { |
| __result.tm_mday = static_cast<unsigned>(__value.day()); |
| __result.tm_mon = static_cast<unsigned>(__value.month()) - 1; |
| } else if constexpr (same_as<_ChronoT, chrono::month_day_last>) { |
| __result.tm_mon = static_cast<unsigned>(__value.month()) - 1; |
| } else if constexpr (same_as<_ChronoT, chrono::month_weekday> || same_as<_ChronoT, chrono::month_weekday_last>) { |
| __result.tm_wday = __value.weekday_indexed().weekday().c_encoding(); |
| __result.tm_mon = static_cast<unsigned>(__value.month()) - 1; |
| } else if constexpr (same_as<_ChronoT, chrono::year_month>) { |
| __result.tm_year = static_cast<int>(__value.year()) - 1900; |
| __result.tm_mon = static_cast<unsigned>(__value.month()) - 1; |
| } else if constexpr (same_as<_ChronoT, chrono::year_month_day> || same_as<_ChronoT, chrono::year_month_day_last>) { |
| return std::__convert_to_tm<_Tm>( |
| chrono::year_month_day{__value}, chrono::weekday{static_cast<chrono::sys_days>(__value)}); |
| } else if constexpr (same_as<_ChronoT, chrono::year_month_weekday> || |
| same_as<_ChronoT, chrono::year_month_weekday_last>) { |
| return std::__convert_to_tm<_Tm>(chrono::year_month_day{static_cast<chrono::sys_days>(__value)}, __value.weekday()); |
| } else if constexpr (__is_hh_mm_ss<_ChronoT>) { |
| __result.tm_sec = __value.seconds().count(); |
| __result.tm_min = __value.minutes().count(); |
| // In libc++ hours is stored as a long. The type in std::tm is an int. So |
| // the overflow can only occur when hour uses more bits than an int |
| // provides. |
| if constexpr (sizeof(std::chrono::hours::rep) > sizeof(__result.tm_hour)) |
| if (__value.hours().count() > std::numeric_limits<decltype(__result.tm_hour)>::max()) |
| std::__throw_format_error("Formatting hh_mm_ss, encountered an hour overflow"); |
| __result.tm_hour = __value.hours().count(); |
| } else |
| static_assert(sizeof(_ChronoT) == 0, "Add the missing type specialization"); |
| |
| return __result; |
| } |
| |
| #endif // if _LIBCPP_STD_VER >= 20 |
| |
| _LIBCPP_END_NAMESPACE_STD |
| |
| _LIBCPP_POP_MACROS |
| |
| #endif // _LIBCPP___CHRONO_CONVERT_TO_TM_H |