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_LEAP_SECOND_H
 13#define _LIBCPP___CHRONO_LEAP_SECOND_H
 14
 15#include <version>
 16// Enable the contents of the header only when libc++ was built with experimental features enabled.
 17#if _LIBCPP_HAS_EXPERIMENTAL_TZDB
 18
 19#  include <__chrono/duration.h>
 20#  include <__chrono/system_clock.h>
 21#  include <__chrono/time_point.h>
 22#  include <__compare/ordering.h>
 23#  include <__compare/three_way_comparable.h>
 24#  include <__config>
 25#  include <__utility/private_constructor_tag.h>
 26
 27#  if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 28#    pragma GCC system_header
 29#  endif
 30
 31_LIBCPP_BEGIN_NAMESPACE_STD
 32
 33#  if _LIBCPP_STD_VER >= 20
 34
 35namespace chrono {
 36
 37class leap_second {
 38public:
 39  [[nodiscard]]
 40  _LIBCPP_HIDE_FROM_ABI explicit constexpr leap_second(__private_constructor_tag, sys_seconds __date, seconds __value)
 41      : __date_(__date), __value_(__value) {}
 42
 43  _LIBCPP_HIDE_FROM_ABI leap_second(const leap_second&)            = default;
 44  _LIBCPP_HIDE_FROM_ABI leap_second& operator=(const leap_second&) = default;
 45
 46  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr sys_seconds date() const noexcept { return __date_; }
 47
 48  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr seconds value() const noexcept { return __value_; }
 49
 50private:
 51  sys_seconds __date_;
 52  seconds __value_;
 53
 54  // The function
 55  //   template<class Duration>
 56  //    requires three_way_comparable_with<sys_seconds, sys_time<Duration>>
 57  //    constexpr auto operator<=>(const leap_second& x, const sys_time<Duration>& y) noexcept;
 58  //
 59  // Has constraints that are recursive (LWG4139). The proposed resolution is
 60  // to make the funcion a hidden friend. For consistency make this change for
 61  // all comparison functions.
 62
 63  _LIBCPP_HIDE_FROM_ABI friend constexpr bool operator==(const leap_second& __x, const leap_second& __y) {
 64    return __x.date() == __y.date();
 65  }
 66
 67  _LIBCPP_HIDE_FROM_ABI friend constexpr strong_ordering operator<=>(const leap_second& __x, const leap_second& __y) {
 68    return __x.date() <=> __y.date();
 69  }
 70
 71  template <class _Duration>
 72  _LIBCPP_HIDE_FROM_ABI friend constexpr bool operator==(const leap_second& __x, const sys_time<_Duration>& __y) {
 73    return __x.date() == __y;
 74  }
 75
 76  template <class _Duration>
 77  _LIBCPP_HIDE_FROM_ABI friend constexpr bool operator<(const leap_second& __x, const sys_time<_Duration>& __y) {
 78    return __x.date() < __y;
 79  }
 80
 81  template <class _Duration>
 82  _LIBCPP_HIDE_FROM_ABI friend constexpr bool operator<(const sys_time<_Duration>& __x, const leap_second& __y) {
 83    return __x < __y.date();
 84  }
 85
 86  template <class _Duration>
 87  _LIBCPP_HIDE_FROM_ABI friend constexpr bool operator>(const leap_second& __x, const sys_time<_Duration>& __y) {
 88    return __y < __x;
 89  }
 90
 91  template <class _Duration>
 92  _LIBCPP_HIDE_FROM_ABI friend constexpr bool operator>(const sys_time<_Duration>& __x, const leap_second& __y) {
 93    return __y < __x;
 94  }
 95
 96  template <class _Duration>
 97  _LIBCPP_HIDE_FROM_ABI friend constexpr bool operator<=(const leap_second& __x, const sys_time<_Duration>& __y) {
 98    return !(__y < __x);
 99  }
100
101  template <class _Duration>
102  _LIBCPP_HIDE_FROM_ABI friend constexpr bool operator<=(const sys_time<_Duration>& __x, const leap_second& __y) {
103    return !(__y < __x);
104  }
105
106  template <class _Duration>
107  _LIBCPP_HIDE_FROM_ABI friend constexpr bool operator>=(const leap_second& __x, const sys_time<_Duration>& __y) {
108    return !(__x < __y);
109  }
110
111  template <class _Duration>
112  _LIBCPP_HIDE_FROM_ABI friend constexpr bool operator>=(const sys_time<_Duration>& __x, const leap_second& __y) {
113    return !(__x < __y);
114  }
115
116  template <class _Duration>
117    requires three_way_comparable_with<sys_seconds, sys_time<_Duration>>
118  _LIBCPP_HIDE_FROM_ABI friend constexpr auto operator<=>(const leap_second& __x, const sys_time<_Duration>& __y) {
119    return __x.date() <=> __y;
120  }
121};
122
123} // namespace chrono
124
125#  endif // _LIBCPP_STD_VER >= 20
126
127_LIBCPP_END_NAMESPACE_STD
128
129#endif // _LIBCPP_HAS_EXPERIMENTAL_TZDB
130
131#endif // _LIBCPP___CHRONO_LEAP_SECOND_H