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
132