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;
weekday(unsigned __val)39   _LIBCPP_HIDE_FROM_ABI inline explicit constexpr weekday(unsigned __val) noexcept
40       : __wd_(static_cast<unsigned char>(__val == 7 ? 0 : __val)) {}
weekday(const sys_days & __sysd)41   _LIBCPP_HIDE_FROM_ABI inline constexpr weekday(const sys_days& __sysd) noexcept
42       : __wd_(__weekday_from_days(__sysd.time_since_epoch().count())) {}
weekday(const local_days & __locd)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;
c_encoding()66   _LIBCPP_HIDE_FROM_ABI inline constexpr unsigned c_encoding() const noexcept { return __wd_; }
iso_encoding()67   _LIBCPP_HIDE_FROM_ABI inline constexpr unsigned iso_encoding() const noexcept { return __wd_ == 0u ? 7 : __wd_; }
ok()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
__weekday_from_days(int __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 _LIBCPP_HIDE_FROM_ABI inline constexpr bool operator<(const weekday& __lhs, const weekday& __rhs) noexcept {
83   return __lhs.c_encoding() < __rhs.c_encoding();
84 }
85 
86 _LIBCPP_HIDE_FROM_ABI inline constexpr bool operator>(const weekday& __lhs, const weekday& __rhs) noexcept {
87   return __rhs < __lhs;
88 }
89 
90 _LIBCPP_HIDE_FROM_ABI inline constexpr bool operator<=(const weekday& __lhs, const weekday& __rhs) noexcept {
91   return !(__rhs < __lhs);
92 }
93 
94 _LIBCPP_HIDE_FROM_ABI inline constexpr bool operator>=(const weekday& __lhs, const weekday& __rhs) noexcept {
95   return !(__lhs < __rhs);
96 }
97 
98 _LIBCPP_HIDE_FROM_ABI inline constexpr weekday operator+(const weekday& __lhs, const days& __rhs) noexcept {
99   auto const __mu = static_cast<long long>(__lhs.c_encoding()) + __rhs.count();
100   auto const __yr = (__mu >= 0 ? __mu : __mu - 6) / 7;
101   return weekday{static_cast<unsigned>(__mu - __yr * 7)};
102 }
103 
104 _LIBCPP_HIDE_FROM_ABI inline constexpr weekday operator+(const days& __lhs, const weekday& __rhs) noexcept {
105   return __rhs + __lhs;
106 }
107 
108 _LIBCPP_HIDE_FROM_ABI inline constexpr weekday operator-(const weekday& __lhs, const days& __rhs) noexcept {
109   return __lhs + -__rhs;
110 }
111 
112 _LIBCPP_HIDE_FROM_ABI inline constexpr days operator-(const weekday& __lhs, const weekday& __rhs) noexcept {
113   const int __wdu = __lhs.c_encoding() - __rhs.c_encoding();
114   const int __wk  = (__wdu >= 0 ? __wdu : __wdu - 6) / 7;
115   return days{__wdu - __wk * 7};
116 }
117 
118 _LIBCPP_HIDE_FROM_ABI inline constexpr weekday& weekday::operator+=(const days& __dd) noexcept {
119   *this = *this + __dd;
120   return *this;
121 }
122 
123 _LIBCPP_HIDE_FROM_ABI inline constexpr weekday& weekday::operator-=(const days& __dd) noexcept {
124   *this = *this - __dd;
125   return *this;
126 }
127 
128 class weekday_indexed {
129 private:
130   chrono::weekday __wd_;
131   unsigned char __idx_;
132 
133 public:
134   weekday_indexed() = default;
weekday_indexed(const chrono::weekday & __wdval,unsigned __idxval)135   _LIBCPP_HIDE_FROM_ABI inline constexpr weekday_indexed(const chrono::weekday& __wdval, unsigned __idxval) noexcept
136       : __wd_{__wdval}, __idx_(__idxval) {}
weekday()137   _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::weekday weekday() const noexcept { return __wd_; }
index()138   _LIBCPP_HIDE_FROM_ABI inline constexpr unsigned index() const noexcept { return __idx_; }
ok()139   _LIBCPP_HIDE_FROM_ABI inline constexpr bool ok() const noexcept { return __wd_.ok() && __idx_ >= 1 && __idx_ <= 5; }
140 };
141 
142 _LIBCPP_HIDE_FROM_ABI inline constexpr bool
143 operator==(const weekday_indexed& __lhs, const weekday_indexed& __rhs) noexcept {
144   return __lhs.weekday() == __rhs.weekday() && __lhs.index() == __rhs.index();
145 }
146 
147 class weekday_last {
148 private:
149   chrono::weekday __wd_;
150 
151 public:
weekday_last(const chrono::weekday & __val)152   _LIBCPP_HIDE_FROM_ABI explicit constexpr weekday_last(const chrono::weekday& __val) noexcept : __wd_{__val} {}
weekday()153   _LIBCPP_HIDE_FROM_ABI constexpr chrono::weekday weekday() const noexcept { return __wd_; }
ok()154   _LIBCPP_HIDE_FROM_ABI constexpr bool ok() const noexcept { return __wd_.ok(); }
155 };
156 
157 _LIBCPP_HIDE_FROM_ABI inline constexpr bool operator==(const weekday_last& __lhs, const weekday_last& __rhs) noexcept {
158   return __lhs.weekday() == __rhs.weekday();
159 }
160 
161 _LIBCPP_HIDE_FROM_ABI inline constexpr weekday_indexed weekday::operator[](unsigned __index) const noexcept {
162   return weekday_indexed{*this, __index};
163 }
164 
165 _LIBCPP_HIDE_FROM_ABI inline constexpr weekday_last weekday::operator[](last_spec) const noexcept {
166   return weekday_last{*this};
167 }
168 
169 inline constexpr weekday Sunday{0};
170 inline constexpr weekday Monday{1};
171 inline constexpr weekday Tuesday{2};
172 inline constexpr weekday Wednesday{3};
173 inline constexpr weekday Thursday{4};
174 inline constexpr weekday Friday{5};
175 inline constexpr weekday Saturday{6};
176 
177 } // namespace chrono
178 
179 _LIBCPP_END_NAMESPACE_STD
180 
181 #endif // _LIBCPP_STD_VER >= 20
182 
183 #endif // _LIBCPP___CHRONO_WEEKDAY_H
184