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 <__cstddef/size_t.h>
26# include <__functional/hash.h>
27# include <__utility/private_constructor_tag.h>
28
29# if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
30# pragma GCC system_header
31# endif
32
33_LIBCPP_BEGIN_NAMESPACE_STD
34
35# if _LIBCPP_STD_VER >= 20
36
37namespace chrono {
38
39class leap_second {
40public:
41 [[nodiscard]]
42 _LIBCPP_HIDE_FROM_ABI explicit constexpr leap_second(__private_constructor_tag, sys_seconds __date, seconds __value)
43 : __date_(__date), __value_(__value) {}
44
45 _LIBCPP_HIDE_FROM_ABI leap_second(const leap_second&) = default;
46 _LIBCPP_HIDE_FROM_ABI leap_second& operator=(const leap_second&) = default;
47
48 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr sys_seconds date() const noexcept { return __date_; }
49
50 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr seconds value() const noexcept { return __value_; }
51
52private:
53 sys_seconds __date_;
54 seconds __value_;
55
56 // The function
57 // template<class Duration>
58 // requires three_way_comparable_with<sys_seconds, sys_time<Duration>>
59 // constexpr auto operator<=>(const leap_second& x, const sys_time<Duration>& y) noexcept;
60 //
61 // Has constraints that are recursive (LWG4139). The proposed resolution is
62 // to make the funcion a hidden friend. For consistency make this change for
63 // all comparison functions.
64
65 _LIBCPP_HIDE_FROM_ABI friend constexpr bool operator==(const leap_second& __x, const leap_second& __y) {
66 return __x.date() == __y.date();
67 }
68
69 _LIBCPP_HIDE_FROM_ABI friend constexpr strong_ordering operator<=>(const leap_second& __x, const leap_second& __y) {
70 return __x.date() <=> __y.date();
71 }
72
73 template <class _Duration>
74 _LIBCPP_HIDE_FROM_ABI friend constexpr bool operator==(const leap_second& __x, const sys_time<_Duration>& __y) {
75 return __x.date() == __y;
76 }
77
78 template <class _Duration>
79 _LIBCPP_HIDE_FROM_ABI friend constexpr bool operator<(const leap_second& __x, const sys_time<_Duration>& __y) {
80 return __x.date() < __y;
81 }
82
83 template <class _Duration>
84 _LIBCPP_HIDE_FROM_ABI friend constexpr bool operator<(const sys_time<_Duration>& __x, const leap_second& __y) {
85 return __x < __y.date();
86 }
87
88 template <class _Duration>
89 _LIBCPP_HIDE_FROM_ABI friend constexpr bool operator>(const leap_second& __x, const sys_time<_Duration>& __y) {
90 return __y < __x;
91 }
92
93 template <class _Duration>
94 _LIBCPP_HIDE_FROM_ABI friend constexpr bool operator>(const sys_time<_Duration>& __x, const leap_second& __y) {
95 return __y < __x;
96 }
97
98 template <class _Duration>
99 _LIBCPP_HIDE_FROM_ABI friend constexpr bool operator<=(const leap_second& __x, const sys_time<_Duration>& __y) {
100 return !(__y < __x);
101 }
102
103 template <class _Duration>
104 _LIBCPP_HIDE_FROM_ABI friend constexpr bool operator<=(const sys_time<_Duration>& __x, const leap_second& __y) {
105 return !(__y < __x);
106 }
107
108 template <class _Duration>
109 _LIBCPP_HIDE_FROM_ABI friend constexpr bool operator>=(const leap_second& __x, const sys_time<_Duration>& __y) {
110 return !(__x < __y);
111 }
112
113 template <class _Duration>
114 _LIBCPP_HIDE_FROM_ABI friend constexpr bool operator>=(const sys_time<_Duration>& __x, const leap_second& __y) {
115 return !(__x < __y);
116 }
117
118 template <class _Duration>
119 requires three_way_comparable_with<sys_seconds, sys_time<_Duration>>
120 _LIBCPP_HIDE_FROM_ABI friend constexpr auto operator<=>(const leap_second& __x, const sys_time<_Duration>& __y) {
121 return __x.date() <=> __y;
122 }
123};
124
125} // namespace chrono
126
127# if _LIBCPP_STD_VER >= 26
128
129template <>
130struct hash<chrono::leap_second> {
131 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI static size_t operator()(const chrono::leap_second& __lp) noexcept {
132 return std::__hash_combine(hash<chrono::sys_seconds>{}(__lp.date()), hash<chrono::seconds>{}(__lp.value()));
133 }
134};
135
136# endif // _LIBCPP_STD_VER >= 26
137
138# endif // _LIBCPP_STD_VER >= 20
139
140_LIBCPP_END_NAMESPACE_STD
141
142#endif // _LIBCPP_HAS_EXPERIMENTAL_TZDB
143
144#endif // _LIBCPP___CHRONO_LEAP_SECOND_H
145