xref: /freebsd/contrib/llvm-project/libcxx/include/__chrono/weekday.h (revision 370e009188ba90c3290b1479aa06ec98b66e140a)
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 _LIBCPP___CHRONO_WEEKDAY_H
11 #define _LIBCPP___CHRONO_WEEKDAY_H
12 
13 #include <__chrono/calendar.h>
14 #include <__chrono/duration.h>
15 #include <__chrono/system_clock.h>
16 #include <__chrono/time_point.h>
17 #include <__config>
18 
19 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
20 #  pragma GCC system_header
21 #endif
22 
23 #if _LIBCPP_STD_VER > 17
24 
25 _LIBCPP_BEGIN_NAMESPACE_STD
26 
27 namespace chrono
28 {
29 
30 class weekday_indexed;
31 class weekday_last;
32 
33 class weekday {
34 private:
35     unsigned char __wd;
36     _LIBCPP_HIDE_FROM_ABI static constexpr unsigned char __weekday_from_days(int __days) noexcept;
37 public:
38   _LIBCPP_HIDE_FROM_ABI weekday() = default;
39   _LIBCPP_HIDE_FROM_ABI inline explicit constexpr weekday(unsigned __val) noexcept : __wd(static_cast<unsigned char>(__val == 7 ? 0 : __val)) {}
40   _LIBCPP_HIDE_FROM_ABI inline constexpr          weekday(const sys_days& __sysd) noexcept
41           : __wd(__weekday_from_days(__sysd.time_since_epoch().count())) {}
42   _LIBCPP_HIDE_FROM_ABI inline explicit constexpr weekday(const local_days& __locd) noexcept
43           : __wd(__weekday_from_days(__locd.time_since_epoch().count())) {}
44 
45   _LIBCPP_HIDE_FROM_ABI inline constexpr weekday& operator++()    noexcept { __wd = (__wd == 6 ? 0 : __wd + 1); return *this; }
46   _LIBCPP_HIDE_FROM_ABI inline constexpr weekday  operator++(int) noexcept { weekday __tmp = *this; ++(*this); return __tmp; }
47   _LIBCPP_HIDE_FROM_ABI inline constexpr weekday& operator--()    noexcept { __wd = (__wd == 0 ? 6 : __wd - 1); return *this; }
48   _LIBCPP_HIDE_FROM_ABI inline constexpr weekday  operator--(int) noexcept { weekday __tmp = *this; --(*this); return __tmp; }
49   _LIBCPP_HIDE_FROM_ABI        constexpr weekday& operator+=(const days& __dd) noexcept;
50   _LIBCPP_HIDE_FROM_ABI        constexpr weekday& operator-=(const days& __dd) noexcept;
51   _LIBCPP_HIDE_FROM_ABI inline constexpr unsigned c_encoding()   const noexcept { return __wd; }
52   _LIBCPP_HIDE_FROM_ABI inline constexpr unsigned iso_encoding() const noexcept { return __wd == 0u ? 7 : __wd; }
53   _LIBCPP_HIDE_FROM_ABI inline constexpr bool ok() const noexcept { return __wd <= 6; }
54   _LIBCPP_HIDE_FROM_ABI        constexpr weekday_indexed operator[](unsigned __index) const noexcept;
55   _LIBCPP_HIDE_FROM_ABI        constexpr weekday_last    operator[](last_spec) const noexcept;
56 };
57 
58 
59 // https://howardhinnant.github.io/date_algorithms.html#weekday_from_days
60 _LIBCPP_HIDE_FROM_ABI inline constexpr
61 unsigned char weekday::__weekday_from_days(int __days) noexcept
62 {
63     return static_cast<unsigned char>(
64               static_cast<unsigned>(__days >= -4 ? (__days+4) % 7 : (__days+5) % 7 + 6)
65            );
66 }
67 
68 _LIBCPP_HIDE_FROM_ABI inline constexpr
69 bool operator==(const weekday& __lhs, const weekday& __rhs) noexcept
70 { return __lhs.c_encoding() == __rhs.c_encoding(); }
71 
72 _LIBCPP_HIDE_FROM_ABI inline constexpr
73 bool operator!=(const weekday& __lhs, const weekday& __rhs) noexcept
74 { return !(__lhs == __rhs); }
75 
76 _LIBCPP_HIDE_FROM_ABI inline constexpr
77 bool operator< (const weekday& __lhs, const weekday& __rhs) noexcept
78 { return __lhs.c_encoding() < __rhs.c_encoding(); }
79 
80 _LIBCPP_HIDE_FROM_ABI inline constexpr
81 bool operator> (const weekday& __lhs, const weekday& __rhs) noexcept
82 { return __rhs < __lhs; }
83 
84 _LIBCPP_HIDE_FROM_ABI inline constexpr
85 bool operator<=(const weekday& __lhs, const weekday& __rhs) noexcept
86 { return !(__rhs < __lhs);}
87 
88 _LIBCPP_HIDE_FROM_ABI inline constexpr
89 bool operator>=(const weekday& __lhs, const weekday& __rhs) noexcept
90 { return !(__lhs < __rhs); }
91 
92 _LIBCPP_HIDE_FROM_ABI constexpr
93 weekday operator+(const weekday& __lhs, const days& __rhs) noexcept
94 {
95     auto const __mu = static_cast<long long>(__lhs.c_encoding()) + __rhs.count();
96     auto const __yr = (__mu >= 0 ? __mu : __mu - 6) / 7;
97     return weekday{static_cast<unsigned>(__mu - __yr * 7)};
98 }
99 
100 _LIBCPP_HIDE_FROM_ABI constexpr
101 weekday operator+(const days& __lhs, const weekday& __rhs) noexcept
102 { return __rhs + __lhs; }
103 
104 _LIBCPP_HIDE_FROM_ABI constexpr
105 weekday operator-(const weekday& __lhs, const days& __rhs) noexcept
106 { return __lhs + -__rhs; }
107 
108 _LIBCPP_HIDE_FROM_ABI constexpr
109 days operator-(const weekday& __lhs, const weekday& __rhs) noexcept
110 {
111     const int __wdu = __lhs.c_encoding() - __rhs.c_encoding();
112     const int __wk = (__wdu >= 0 ? __wdu : __wdu-6) / 7;
113     return days{__wdu - __wk * 7};
114 }
115 
116 _LIBCPP_HIDE_FROM_ABI inline constexpr
117 weekday& weekday::operator+=(const days& __dd) noexcept
118 { *this = *this + __dd; return *this; }
119 
120 _LIBCPP_HIDE_FROM_ABI inline constexpr
121 weekday& weekday::operator-=(const days& __dd) noexcept
122 { *this = *this - __dd; return *this; }
123 
124 class weekday_indexed {
125 private:
126     chrono::weekday __wd;
127     unsigned char   __idx;
128 public:
129     _LIBCPP_HIDE_FROM_ABI weekday_indexed() = default;
130     _LIBCPP_HIDE_FROM_ABI inline constexpr weekday_indexed(const chrono::weekday& __wdval, unsigned __idxval) noexcept
131         : __wd{__wdval}, __idx(__idxval) {}
132     _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::weekday weekday() const noexcept { return __wd; }
133     _LIBCPP_HIDE_FROM_ABI inline constexpr unsigned                 index() const noexcept { return __idx; }
134     _LIBCPP_HIDE_FROM_ABI inline constexpr bool ok() const noexcept { return __wd.ok() && __idx >= 1 && __idx <= 5; }
135 };
136 
137 _LIBCPP_HIDE_FROM_ABI inline constexpr
138 bool operator==(const weekday_indexed& __lhs, const weekday_indexed& __rhs) noexcept
139 { return __lhs.weekday() == __rhs.weekday() && __lhs.index() == __rhs.index(); }
140 
141 _LIBCPP_HIDE_FROM_ABI inline constexpr
142 bool operator!=(const weekday_indexed& __lhs, const weekday_indexed& __rhs) noexcept
143 { return !(__lhs == __rhs); }
144 
145 
146 class weekday_last {
147 private:
148     chrono::weekday __wd;
149 public:
150     _LIBCPP_HIDE_FROM_ABI explicit constexpr weekday_last(const chrono::weekday& __val) noexcept
151         : __wd{__val} {}
152     _LIBCPP_HIDE_FROM_ABI constexpr chrono::weekday weekday() const noexcept { return __wd; }
153     _LIBCPP_HIDE_FROM_ABI constexpr bool ok() const noexcept { return __wd.ok(); }
154 };
155 
156 _LIBCPP_HIDE_FROM_ABI inline constexpr
157 bool operator==(const weekday_last& __lhs, const weekday_last& __rhs) noexcept
158 { return __lhs.weekday() == __rhs.weekday(); }
159 
160 _LIBCPP_HIDE_FROM_ABI inline constexpr
161 bool operator!=(const weekday_last& __lhs, const weekday_last& __rhs) noexcept
162 { return !(__lhs == __rhs); }
163 
164 _LIBCPP_HIDE_FROM_ABI inline constexpr
165 weekday_indexed weekday::operator[](unsigned __index) const noexcept { return weekday_indexed{*this, __index}; }
166 
167 _LIBCPP_HIDE_FROM_ABI inline constexpr
168 weekday_last weekday::operator[](last_spec) const noexcept { return weekday_last{*this}; }
169 
170 
171 inline constexpr weekday   Sunday{0};
172 inline constexpr weekday   Monday{1};
173 inline constexpr weekday   Tuesday{2};
174 inline constexpr weekday   Wednesday{3};
175 inline constexpr weekday   Thursday{4};
176 inline constexpr weekday   Friday{5};
177 inline constexpr weekday   Saturday{6};
178 
179 } // namespace chrono
180 
181 _LIBCPP_END_NAMESPACE_STD
182 
183 #endif // _LIBCPP_STD_VER > 17
184 
185 #endif // _LIBCPP___CHRONO_WEEKDAY_H
186