1 // -*- C++ -*- 2 //===----------------------------------------------------------------------===// 3 // 4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 5 // See https://llvm.org/LICENSE.txt for license information. 6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 7 // 8 //===----------------------------------------------------------------------===// 9 10 // For information see https://libcxx.llvm.org/DesignDocs/TimeZone.html 11 12 #ifndef _LIBCPP___CHRONO_TZDB_H 13 #define _LIBCPP___CHRONO_TZDB_H 14 15 #include <version> 16 // Enable the contents of the header only when libc++ was built with experimental features enabled. 17 #if !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_TZDB) 18 19 # include <__algorithm/ranges_lower_bound.h> 20 # include <__chrono/leap_second.h> 21 # include <__chrono/time_zone.h> 22 # include <__chrono/time_zone_link.h> 23 # include <__config> 24 # include <string> 25 # include <vector> 26 27 # if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 28 # pragma GCC system_header 29 # endif 30 31 _LIBCPP_PUSH_MACROS 32 # include <__undef_macros> 33 34 _LIBCPP_BEGIN_NAMESPACE_STD 35 36 # if _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_TIME_ZONE_DATABASE) && !defined(_LIBCPP_HAS_NO_FILESYSTEM) && \ 37 !defined(_LIBCPP_HAS_NO_LOCALIZATION) 38 39 namespace chrono { 40 41 struct tzdb { 42 string version; 43 vector<time_zone> zones; 44 vector<time_zone_link> links; 45 46 vector<leap_second> leap_seconds; 47 48 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI const time_zone* __locate_zone(string_view __name) const { 49 if (const time_zone* __result = __find_in_zone(__name)) 50 return __result; 51 52 if (auto __it = ranges::lower_bound(links, __name, {}, &time_zone_link::name); 53 __it != links.end() && __it->name() == __name) 54 if (const time_zone* __result = __find_in_zone(__it->target())) 55 return __result; 56 57 return nullptr; 58 } 59 60 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI const time_zone* locate_zone(string_view __name) const { 61 if (const time_zone* __result = __locate_zone(__name)) 62 return __result; 63 64 std::__throw_runtime_error("tzdb: requested time zone not found"); 65 } 66 67 [[nodiscard]] _LIBCPP_AVAILABILITY_TZDB _LIBCPP_HIDE_FROM_ABI const time_zone* current_zone() const { 68 return __current_zone(); 69 } 70 71 private: 72 _LIBCPP_HIDE_FROM_ABI const time_zone* __find_in_zone(string_view __name) const noexcept { 73 if (auto __it = ranges::lower_bound(zones, __name, {}, &time_zone::name); 74 __it != zones.end() && __it->name() == __name) 75 return std::addressof(*__it); 76 77 return nullptr; 78 } 79 80 [[nodiscard]] _LIBCPP_AVAILABILITY_TZDB _LIBCPP_EXPORTED_FROM_ABI const time_zone* __current_zone() const; 81 }; 82 83 } // namespace chrono 84 85 # endif // _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_TIME_ZONE_DATABASE) && !defined(_LIBCPP_HAS_NO_FILESYSTEM) 86 // && !defined(_LIBCPP_HAS_NO_LOCALIZATION) 87 88 _LIBCPP_END_NAMESPACE_STD 89 90 _LIBCPP_POP_MACROS 91 92 #endif // !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_TZDB) 93 94 #endif // _LIBCPP___CHRONO_TZDB_H 95