libcxx/include/__chrono/weekday.h

   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
  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   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.c_encoding() < __rhs.c_encoding(); }
  75
  76 _LIBCPP_HIDE_FROM_ABI inline constexpr
  77 bool operator> (const weekday& __lhs, const weekday& __rhs) noexcept
  78 { return __rhs < __lhs; }
  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 !(__lhs < __rhs); }
  87
  88 _LIBCPP_HIDE_FROM_ABI constexpr
  89 weekday operator+(const weekday& __lhs, const days& __rhs) noexcept
  90 {
  91     auto const __mu = static_cast<long long>(__lhs.c_encoding()) + __rhs.count();
  92     auto const __yr = (__mu >= 0 ? __mu : __mu - 6) / 7;
  93     return weekday{static_cast<unsigned>(__mu - __yr * 7)};
  94 }
  95
  96 _LIBCPP_HIDE_FROM_ABI constexpr
  97 weekday operator+(const days& __lhs, const weekday& __rhs) noexcept
  98 { return __rhs + __lhs; }
  99
 100 _LIBCPP_HIDE_FROM_ABI constexpr
 101 weekday operator-(const weekday& __lhs, const days& __rhs) noexcept
 102 { return __lhs + -__rhs; }
 103
 104 _LIBCPP_HIDE_FROM_ABI constexpr
 105 days operator-(const weekday& __lhs, const weekday& __rhs) noexcept
 106 {
 107     const int __wdu = __lhs.c_encoding() - __rhs.c_encoding();
 108     const int __wk = (__wdu >= 0 ? __wdu : __wdu-6) / 7;
 109     return days{__wdu - __wk * 7};
 110 }
 111
 112 _LIBCPP_HIDE_FROM_ABI inline constexpr
 113 weekday& weekday::operator+=(const days& __dd) noexcept
 114 { *this = *this + __dd; return *this; }
 115
 116 _LIBCPP_HIDE_FROM_ABI inline constexpr
 117 weekday& weekday::operator-=(const days& __dd) noexcept
 118 { *this = *this - __dd; return *this; }
 119
 120 class weekday_indexed {
 121 private:
 122     chrono::weekday __wd_;
 123     unsigned char   __idx_;
 124 public:
 125     weekday_indexed() = default;
 126     _LIBCPP_HIDE_FROM_ABI inline constexpr weekday_indexed(const chrono::weekday& __wdval, unsigned __idxval) noexcept
 127         : __wd_{__wdval}, __idx_(__idxval) {}
 128     _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::weekday weekday() const noexcept { return __wd_; }
 129     _LIBCPP_HIDE_FROM_ABI inline constexpr unsigned                 index() const noexcept { return __idx_; }
 130     _LIBCPP_HIDE_FROM_ABI inline constexpr bool ok() const noexcept { return __wd_.ok() && __idx_ >= 1 && __idx_ <= 5; }
 131 };
 132
 133 _LIBCPP_HIDE_FROM_ABI inline constexpr
 134 bool operator==(const weekday_indexed& __lhs, const weekday_indexed& __rhs) noexcept
 135 { return __lhs.weekday() == __rhs.weekday() && __lhs.index() == __rhs.index(); }
 136
 137 class weekday_last {
 138 private:
 139     chrono::weekday __wd_;
 140 public:
 141     _LIBCPP_HIDE_FROM_ABI explicit constexpr weekday_last(const chrono::weekday& __val) noexcept
 142         : __wd_{__val} {}
 143     _LIBCPP_HIDE_FROM_ABI constexpr chrono::weekday weekday() const noexcept { return __wd_; }
 144     _LIBCPP_HIDE_FROM_ABI constexpr bool ok() const noexcept { return __wd_.ok(); }
 145 };
 146
 147 _LIBCPP_HIDE_FROM_ABI inline constexpr
 148 bool operator==(const weekday_last& __lhs, const weekday_last& __rhs) noexcept
 149 { return __lhs.weekday() == __rhs.weekday(); }
 150
 151 _LIBCPP_HIDE_FROM_ABI inline constexpr
 152 weekday_indexed weekday::operator[](unsigned __index) const noexcept { return weekday_indexed{*this, __index}; }
 153
 154 _LIBCPP_HIDE_FROM_ABI inline constexpr
 155 weekday_last weekday::operator[](last_spec) const noexcept { return weekday_last{*this}; }
 156
 157
 158 inline constexpr weekday   Sunday{0};
 159 inline constexpr weekday   Monday{1};
 160 inline constexpr weekday   Tuesday{2};
 161 inline constexpr weekday   Wednesday{3};
 162 inline constexpr weekday   Thursday{4};
 163 inline constexpr weekday   Friday{5};
 164 inline constexpr weekday   Saturday{6};
 165
 166 } // namespace chrono
 167
 168 _LIBCPP_END_NAMESPACE_STD
 169
 170 #endif // _LIBCPP_STD_VER >= 20
 171
 172 #endif // _LIBCPP___CHRONO_WEEKDAY_H