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 #ifndef TEST_STD_TIME_TIME_ZONE_TIME_ZONE_ZONEDTIME_TEST_OFFSET_TIME_ZONE_H 11 #define TEST_STD_TIME_TIME_ZONE_TIME_ZONE_ZONEDTIME_TEST_OFFSET_TIME_ZONE_H 12 13 #include <cassert> 14 #include <charconv> 15 #include <chrono> 16 #include <format> 17 #include <string_view> 18 #include <system_error> 19 #include <type_traits> 20 21 enum class offset_time_zone_flags { 22 none = 0, 23 has_default_zone = 1, 24 has_locate_zone = 2, 25 both = has_default_zone | has_locate_zone 26 }; 27 28 // The enforcement of the flags is done in the zoned_traits 29 template <offset_time_zone_flags flags = offset_time_zone_flags::both> 30 class offset_time_zone { 31 public: 32 offset_time_zone() : offset_{std::chrono::seconds{0}} {} 33 explicit offset_time_zone(std::string_view name) { 34 int count; 35 const char* begin = name.data(); 36 const char* end = begin + name.size(); 37 std::from_chars_result result = std::from_chars(begin, end, count); 38 assert(result == std::from_chars_result(end, std::errc{})); 39 40 offset_ = std::chrono::seconds(count); 41 } 42 43 std::chrono::seconds offset() const { return offset_; } 44 45 offset_time_zone* operator->() { return this; } 46 47 const offset_time_zone* operator->() const { return this; } 48 49 template <class Duration> 50 std::chrono::sys_time<std::common_type_t<Duration, std::chrono::seconds>> 51 to_sys(const std::chrono::local_time<Duration>& local) const { 52 return std::chrono::sys_time<std::common_type_t<Duration, std::chrono::seconds>>{ 53 local.time_since_epoch() + offset_}; 54 } 55 56 template <class Duration> 57 std::chrono::local_time<std::common_type_t<Duration, std::chrono::seconds>> 58 to_local(const std::chrono::sys_time<Duration>& sys) const { 59 return std::chrono::local_time<std::common_type_t<Duration, std::chrono::seconds>>{ 60 sys.time_since_epoch() - offset_}; 61 } 62 63 template <class Duration> 64 std::chrono::sys_info get_info(const std::chrono::sys_time<Duration>&) const { 65 return {std::chrono::sys_seconds::min(), 66 std::chrono::sys_seconds::max(), 67 offset_, 68 std::chrono::minutes{0}, 69 std::format("{:+03d}s", offset_.count())}; 70 } 71 72 private: 73 std::chrono::seconds offset_; 74 }; 75 76 template <> 77 struct std::chrono::zoned_traits<offset_time_zone<offset_time_zone_flags::has_default_zone>> { 78 using type = offset_time_zone<offset_time_zone_flags::has_default_zone>; 79 80 static type default_zone() { return {}; } 81 }; 82 83 template <> 84 struct std::chrono::zoned_traits<offset_time_zone<offset_time_zone_flags::has_locate_zone>> { 85 using type = offset_time_zone<offset_time_zone_flags::has_locate_zone>; 86 87 static type locate_zone(std::string_view name) { return type{name}; } 88 }; 89 90 template <> 91 struct std::chrono::zoned_traits<offset_time_zone<offset_time_zone_flags::both>> { 92 using type = offset_time_zone<offset_time_zone_flags::both>; 93 94 static type default_zone() { return {}; } 95 static type locate_zone(std::string_view name) { return type{name}; } 96 }; 97 98 #endif // TEST_STD_TIME_TIME_ZONE_TIME_ZONE_ZONEDTIME_TEST_OFFSET_TIME_ZONE_H 99