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 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