xref: /freebsd/contrib/llvm-project/libcxx/include/__chrono/weekday.h (revision 7fdf597e96a02165cfe22ff357b857d5fa15ed8a)
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 >= 20
24 
25 _LIBCPP_BEGIN_NAMESPACE_STD
26 
27 namespace chrono {
28 
29 class weekday_indexed;
30 class weekday_last;
31 
32 class weekday {
33 private:
34   unsigned char __wd_;
35   _LIBCPP_HIDE_FROM_ABI static constexpr unsigned char __weekday_from_days(int __days) noexcept;
36 
37 public:
38   weekday() = default;
39   _LIBCPP_HIDE_FROM_ABI inline explicit constexpr weekday(unsigned __val) noexcept
40       : __wd_(static_cast<unsigned char>(__val == 7 ? 0 : __val)) {}
41   _LIBCPP_HIDE_FROM_ABI inline constexpr weekday(const sys_days& __sysd) noexcept
42       : __wd_(__weekday_from_days(__sysd.time_since_epoch().count())) {}
43   _LIBCPP_HIDE_FROM_ABI inline explicit constexpr weekday(const local_days& __locd) noexcept
44       : __wd_(__weekday_from_days(__locd.time_since_epoch().count())) {}
45 
46   _LIBCPP_HIDE_FROM_ABI inline constexpr weekday& operator++() noexcept {
47     __wd_ = (__wd_ == 6 ? 0 : __wd_ + 1);
48     return *this;
49   }
50   _LIBCPP_HIDE_FROM_ABI inline constexpr weekday operator++(int) noexcept {
51     weekday __tmp = *this;
52     ++(*this);
53     return __tmp;
54   }
55   _LIBCPP_HIDE_FROM_ABI inline constexpr weekday& operator--() noexcept {
56     __wd_ = (__wd_ == 0 ? 6 : __wd_ - 1);
57     return *this;
58   }
59   _LIBCPP_HIDE_FROM_ABI inline constexpr weekday operator--(int) noexcept {
60     weekday __tmp = *this;
61     --(*this);
62     return __tmp;
63   }
64   _LIBCPP_HIDE_FROM_ABI constexpr weekday& operator+=(const days& __dd) noexcept;
65   _LIBCPP_HIDE_FROM_ABI constexpr weekday& operator-=(const days& __dd) noexcept;
66   _LIBCPP_HIDE_FROM_ABI inline constexpr unsigned c_encoding() const noexcept { return __wd_; }
67   _LIBCPP_HIDE_FROM_ABI inline constexpr unsigned iso_encoding() const noexcept { return __wd_ == 0u ? 7 : __wd_; }
68   _LIBCPP_HIDE_FROM_ABI inline constexpr bool ok() const noexcept { return __wd_ <= 6; }
69   _LIBCPP_HIDE_FROM_ABI constexpr weekday_indexed operator[](unsigned __index) const noexcept;
70   _LIBCPP_HIDE_FROM_ABI constexpr weekday_last operator[](last_spec) const noexcept;
71 };
72 
73 // https://howardhinnant.github.io/date_algorithms.html#weekday_from_days
74 _LIBCPP_HIDE_FROM_ABI inline constexpr unsigned char weekday::__weekday_from_days(int __days) noexcept {
75   return static_cast<unsigned char>(static_cast<unsigned>(__days >= -4 ? (__days + 4) % 7 : (__days + 5) % 7 + 6));
76 }
77 
78 _LIBCPP_HIDE_FROM_ABI inline constexpr bool operator==(const weekday& __lhs, const weekday& __rhs) noexcept {
79   return __lhs.c_encoding() == __rhs.c_encoding();
80 }
81 
82 // TODO(LLVM 20): Remove the escape hatch
83 #  ifdef _LIBCPP_ENABLE_REMOVED_WEEKDAY_RELATIONAL_OPERATORS
84 _LIBCPP_HIDE_FROM_ABI inline constexpr bool operator<(const weekday& __lhs, const weekday& __rhs) noexcept {
85   return __lhs.c_encoding() < __rhs.c_encoding();
86 }
87 
88 _LIBCPP_HIDE_FROM_ABI inline constexpr bool operator>(const weekday& __lhs, const weekday& __rhs) noexcept {
89   return __rhs < __lhs;
90 }
91 
92 _LIBCPP_HIDE_FROM_ABI inline constexpr bool operator<=(const weekday& __lhs, const weekday& __rhs) noexcept {
93   return !(__rhs < __lhs);
94 }
95 
96 _LIBCPP_HIDE_FROM_ABI inline constexpr bool operator>=(const weekday& __lhs, const weekday& __rhs) noexcept {
97   return !(__lhs < __rhs);
98 }
99 #  endif // _LIBCPP_ENABLE_REMOVED_WEEKDAY_RELATIONAL_OPERATORS
100 
101 _LIBCPP_HIDE_FROM_ABI inline constexpr weekday operator+(const weekday& __lhs, const days& __rhs) noexcept {
102   auto const __mu = static_cast<long long>(__lhs.c_encoding()) + __rhs.count();
103   auto const __yr = (__mu >= 0 ? __mu : __mu - 6) / 7;
104   return weekday{static_cast<unsigned>(__mu - __yr * 7)};
105 }
106 
107 _LIBCPP_HIDE_FROM_ABI inline constexpr weekday operator+(const days& __lhs, const weekday& __rhs) noexcept {
108   return __rhs + __lhs;
109 }
110 
111 _LIBCPP_HIDE_FROM_ABI inline constexpr weekday operator-(const weekday& __lhs, const days& __rhs) noexcept {
112   return __lhs + -__rhs;
113 }
114 
115 _LIBCPP_HIDE_FROM_ABI inline constexpr days operator-(const weekday& __lhs, const weekday& __rhs) noexcept {
116   const int __wdu = __lhs.c_encoding() - __rhs.c_encoding();
117   const int __wk  = (__wdu >= 0 ? __wdu : __wdu - 6) / 7;
118   return days{__wdu - __wk * 7};
119 }
120 
121 _LIBCPP_HIDE_FROM_ABI inline constexpr weekday& weekday::operator+=(const days& __dd) noexcept {
122   *this = *this + __dd;
123   return *this;
124 }
125 
126 _LIBCPP_HIDE_FROM_ABI inline constexpr weekday& weekday::operator-=(const days& __dd) noexcept {
127   *this = *this - __dd;
128   return *this;
129 }
130 
131 class weekday_indexed {
132 private:
133   chrono::weekday __wd_;
134   unsigned char __idx_;
135 
136 public:
137   weekday_indexed() = default;
138   _LIBCPP_HIDE_FROM_ABI inline constexpr weekday_indexed(const chrono::weekday& __wdval, unsigned __idxval) noexcept
139       : __wd_{__wdval}, __idx_(__idxval) {}
140   _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::weekday weekday() const noexcept { return __wd_; }
141   _LIBCPP_HIDE_FROM_ABI inline constexpr unsigned index() const noexcept { return __idx_; }
142   _LIBCPP_HIDE_FROM_ABI inline constexpr bool ok() const noexcept { return __wd_.ok() && __idx_ >= 1 && __idx_ <= 5; }
143 };
144 
145 _LIBCPP_HIDE_FROM_ABI inline constexpr bool
146 operator==(const weekday_indexed& __lhs, const weekday_indexed& __rhs) noexcept {
147   return __lhs.weekday() == __rhs.weekday() && __lhs.index() == __rhs.index();
148 }
149 
150 class weekday_last {
151 private:
152   chrono::weekday __wd_;
153 
154 public:
155   _LIBCPP_HIDE_FROM_ABI explicit constexpr weekday_last(const chrono::weekday& __val) noexcept : __wd_{__val} {}
156   _LIBCPP_HIDE_FROM_ABI constexpr chrono::weekday weekday() const noexcept { return __wd_; }
157   _LIBCPP_HIDE_FROM_ABI constexpr bool ok() const noexcept { return __wd_.ok(); }
158 };
159 
160 _LIBCPP_HIDE_FROM_ABI inline constexpr bool operator==(const weekday_last& __lhs, const weekday_last& __rhs) noexcept {
161   return __lhs.weekday() == __rhs.weekday();
162 }
163 
164 _LIBCPP_HIDE_FROM_ABI inline constexpr weekday_indexed weekday::operator[](unsigned __index) const noexcept {
165   return weekday_indexed{*this, __index};
166 }
167 
168 _LIBCPP_HIDE_FROM_ABI inline constexpr weekday_last weekday::operator[](last_spec) const noexcept {
169   return weekday_last{*this};
170 }
171 
172 inline constexpr weekday Sunday{0};
173 inline constexpr weekday Monday{1};
174 inline constexpr weekday Tuesday{2};
175 inline constexpr weekday Wednesday{3};
176 inline constexpr weekday Thursday{4};
177 inline constexpr weekday Friday{5};
178 inline constexpr weekday Saturday{6};
179 
180 } // namespace chrono
181 
182 _LIBCPP_END_NAMESPACE_STD
183 
184 #endif // _LIBCPP_STD_VER >= 20
185 
186 #endif // _LIBCPP___CHRONO_WEEKDAY_H
187