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1// -*- C++ -*-
2//===---------------------------- chrono ----------------------------------===//
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
11#define _LIBCPP_CHRONO
12
13/*
14    chrono synopsis
15
16namespace std
17{
18namespace chrono
19{
20
21template <class ToDuration, class Rep, class Period>
22constexpr
23ToDuration
24duration_cast(const duration<Rep, Period>& fd);
25
26template <class Rep> struct treat_as_floating_point : is_floating_point<Rep> {};
27
28template <class Rep> inline constexpr bool treat_as_floating_point_v
29    = treat_as_floating_point<Rep>::value;                       // C++17
30
31template <class Rep>
32struct duration_values
33{
34public:
35    static constexpr Rep zero(); // noexcept in C++20
36    static constexpr Rep max();  // noexcept in C++20
37    static constexpr Rep min();  // noexcept in C++20
38};
39
40// duration
41
42template <class Rep, class Period = ratio<1>>
43class duration
44{
45    static_assert(!__is_duration<Rep>::value, "A duration representation can not be a duration");
46    static_assert(__is_ratio<Period>::value, "Second template parameter of duration must be a std::ratio");
47    static_assert(Period::num > 0, "duration period must be positive");
48public:
49    typedef Rep rep;
50    typedef typename _Period::type period;
51
52    constexpr duration() = default;
53    template <class Rep2>
54        constexpr explicit duration(const Rep2& r,
55            typename enable_if
56            <
57               is_convertible<Rep2, rep>::value &&
58               (treat_as_floating_point<rep>::value ||
59               !treat_as_floating_point<rep>::value && !treat_as_floating_point<Rep2>::value)
60            >::type* = 0);
61
62    // conversions
63    template <class Rep2, class Period2>
64        constexpr duration(const duration<Rep2, Period2>& d,
65            typename enable_if
66            <
67                treat_as_floating_point<rep>::value ||
68                ratio_divide<Period2, period>::type::den == 1
69            >::type* = 0);
70
71    // observer
72
73    constexpr rep count() const;
74
75    // arithmetic
76
77    constexpr common_type<duration>::type  operator+() const;
78    constexpr common_type<duration>::type  operator-() const;
79    constexpr duration& operator++();    // constexpr in C++17
80    constexpr duration  operator++(int); // constexpr in C++17
81    constexpr duration& operator--();    // constexpr in C++17
82    constexpr duration  operator--(int); // constexpr in C++17
83
84    constexpr duration& operator+=(const duration& d);  // constexpr in C++17
85    constexpr duration& operator-=(const duration& d);  // constexpr in C++17
86
87    duration& operator*=(const rep& rhs);       // constexpr in C++17
88    duration& operator/=(const rep& rhs);       // constexpr in C++17
89    duration& operator%=(const rep& rhs);       // constexpr in C++17
90    duration& operator%=(const duration& rhs);  // constexpr in C++17
91
92    // special values
93
94    static constexpr duration zero(); // noexcept in C++20
95    static constexpr duration min();  // noexcept in C++20
96    static constexpr duration max();  // noexcept in C++20
97};
98
99typedef duration<long long,         nano> nanoseconds;
100typedef duration<long long,        micro> microseconds;
101typedef duration<long long,        milli> milliseconds;
102typedef duration<long long              > seconds;
103typedef duration<     long, ratio<  60> > minutes;
104typedef duration<     long, ratio<3600> > hours;
105
106template <class Clock, class Duration = typename Clock::duration>
107class time_point
108{
109public:
110    typedef Clock                     clock;
111    typedef Duration                  duration;
112    typedef typename duration::rep    rep;
113    typedef typename duration::period period;
114private:
115    duration d_;  // exposition only
116
117public:
118    time_point();  // has value "epoch" // constexpr in C++14
119    explicit time_point(const duration& d);  // same as time_point() + d // constexpr in C++14
120
121    // conversions
122    template <class Duration2>
123       time_point(const time_point<clock, Duration2>& t); // constexpr in C++14
124
125    // observer
126
127    duration time_since_epoch() const; // constexpr in C++14
128
129    // arithmetic
130
131    time_point& operator+=(const duration& d); // constexpr in C++17
132    time_point& operator-=(const duration& d); // constexpr in C++17
133
134    // special values
135
136    static constexpr time_point min();  // noexcept in C++20
137    static constexpr time_point max();  // noexcept in C++20
138};
139
140} // chrono
141
142// common_type traits
143template <class Rep1, class Period1, class Rep2, class Period2>
144  struct common_type<chrono::duration<Rep1, Period1>, chrono::duration<Rep2, Period2>>;
145
146template <class Clock, class Duration1, class Duration2>
147  struct common_type<chrono::time_point<Clock, Duration1>, chrono::time_point<Clock, Duration2>>;
148
149namespace chrono {
150
151
152template<class T> struct is_clock;  // C++20
153template<class T> inline constexpr bool is_clock_v = is_clock<T>::value;   // C++20
154
155
156// duration arithmetic
157template <class Rep1, class Period1, class Rep2, class Period2>
158  constexpr
159  typename common_type<duration<Rep1, Period1>, duration<Rep2, Period2>>::type
160  operator+(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
161template <class Rep1, class Period1, class Rep2, class Period2>
162  constexpr
163  typename common_type<duration<Rep1, Period1>, duration<Rep2, Period2>>::type
164  operator-(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
165template <class Rep1, class Period, class Rep2>
166  constexpr
167  duration<typename common_type<Rep1, Rep2>::type, Period>
168  operator*(const duration<Rep1, Period>& d, const Rep2& s);
169template <class Rep1, class Period, class Rep2>
170  constexpr
171  duration<typename common_type<Rep1, Rep2>::type, Period>
172  operator*(const Rep1& s, const duration<Rep2, Period>& d);
173template <class Rep1, class Period, class Rep2>
174  constexpr
175  duration<typename common_type<Rep1, Rep2>::type, Period>
176  operator/(const duration<Rep1, Period>& d, const Rep2& s);
177template <class Rep1, class Period1, class Rep2, class Period2>
178  constexpr
179  typename common_type<Rep1, Rep2>::type
180  operator/(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
181
182// duration comparisons
183template <class Rep1, class Period1, class Rep2, class Period2>
184   constexpr
185   bool operator==(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
186template <class Rep1, class Period1, class Rep2, class Period2>
187   constexpr
188   bool operator!=(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
189template <class Rep1, class Period1, class Rep2, class Period2>
190   constexpr
191   bool operator< (const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
192template <class Rep1, class Period1, class Rep2, class Period2>
193   constexpr
194   bool operator<=(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
195template <class Rep1, class Period1, class Rep2, class Period2>
196   constexpr
197   bool operator> (const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
198template <class Rep1, class Period1, class Rep2, class Period2>
199   constexpr
200   bool operator>=(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
201
202// duration_cast
203template <class ToDuration, class Rep, class Period>
204  ToDuration duration_cast(const duration<Rep, Period>& d);
205
206template <class ToDuration, class Rep, class Period>
207    constexpr ToDuration floor(const duration<Rep, Period>& d);    // C++17
208template <class ToDuration, class Rep, class Period>
209    constexpr ToDuration ceil(const duration<Rep, Period>& d);     // C++17
210template <class ToDuration, class Rep, class Period>
211    constexpr ToDuration round(const duration<Rep, Period>& d);    // C++17
212
213// duration I/O is elsewhere
214
215// time_point arithmetic (all constexpr in C++14)
216template <class Clock, class Duration1, class Rep2, class Period2>
217  time_point<Clock, typename common_type<Duration1, duration<Rep2, Period2>>::type>
218  operator+(const time_point<Clock, Duration1>& lhs, const duration<Rep2, Period2>& rhs);
219template <class Rep1, class Period1, class Clock, class Duration2>
220  time_point<Clock, typename common_type<duration<Rep1, Period1>, Duration2>::type>
221  operator+(const duration<Rep1, Period1>& lhs, const time_point<Clock, Duration2>& rhs);
222template <class Clock, class Duration1, class Rep2, class Period2>
223  time_point<Clock, typename common_type<Duration1, duration<Rep2, Period2>>::type>
224  operator-(const time_point<Clock, Duration1>& lhs, const duration<Rep2, Period2>& rhs);
225template <class Clock, class Duration1, class Duration2>
226  typename common_type<Duration1, Duration2>::type
227  operator-(const time_point<Clock, Duration1>& lhs, const time_point<Clock, Duration2>& rhs);
228
229// time_point comparisons (all constexpr in C++14)
230template <class Clock, class Duration1, class Duration2>
231   bool operator==(const time_point<Clock, Duration1>& lhs, const time_point<Clock, Duration2>& rhs);
232template <class Clock, class Duration1, class Duration2>
233   bool operator!=(const time_point<Clock, Duration1>& lhs, const time_point<Clock, Duration2>& rhs);
234template <class Clock, class Duration1, class Duration2>
235   bool operator< (const time_point<Clock, Duration1>& lhs, const time_point<Clock, Duration2>& rhs);
236template <class Clock, class Duration1, class Duration2>
237   bool operator<=(const time_point<Clock, Duration1>& lhs, const time_point<Clock, Duration2>& rhs);
238template <class Clock, class Duration1, class Duration2>
239   bool operator> (const time_point<Clock, Duration1>& lhs, const time_point<Clock, Duration2>& rhs);
240template <class Clock, class Duration1, class Duration2>
241   bool operator>=(const time_point<Clock, Duration1>& lhs, const time_point<Clock, Duration2>& rhs);
242
243// time_point_cast (constexpr in C++14)
244
245template <class ToDuration, class Clock, class Duration>
246  time_point<Clock, ToDuration> time_point_cast(const time_point<Clock, Duration>& t);
247
248template <class ToDuration, class Clock, class Duration>
249    constexpr time_point<Clock, ToDuration>
250    floor(const time_point<Clock, Duration>& tp);                  // C++17
251
252template <class ToDuration, class Clock, class Duration>
253    constexpr time_point<Clock, ToDuration>
254    ceil(const time_point<Clock, Duration>& tp);                   // C++17
255
256template <class ToDuration, class Clock, class Duration>
257    constexpr time_point<Clock, ToDuration>
258    round(const time_point<Clock, Duration>& tp);                  // C++17
259
260template <class Rep, class Period>
261    constexpr duration<Rep, Period> abs(duration<Rep, Period> d);  // C++17
262
263// Clocks
264
265class system_clock
266{
267public:
268    typedef microseconds                     duration;
269    typedef duration::rep                    rep;
270    typedef duration::period                 period;
271    typedef chrono::time_point<system_clock> time_point;
272    static const bool is_steady =            false; // constexpr in C++14
273
274    static time_point now() noexcept;
275    static time_t     to_time_t  (const time_point& __t) noexcept;
276    static time_point from_time_t(time_t __t) noexcept;
277};
278
279template <class Duration>
280  using sys_time  = time_point<system_clock, Duration>; // C++20
281using sys_seconds = sys_time<seconds>;                  // C++20
282using sys_days    = sys_time<days>;                     // C++20
283
284class utc_clock;                                        // C++20
285
286template <class Duration>
287  using utc_time  = time_point<utc_clock, Duration>;    // C++20
288using utc_seconds = utc_time<seconds>;                  // C++20
289
290class tai_clock;                                        // C++20
291
292template <class Duration>
293  using tai_time  = time_point<tai_clock, Duration>;    // C++20
294using tai_seconds = tai_time<seconds>;                  // C++20
295
296class file_clock;                                       // C++20
297
298template<class Duration>
299  using file_time = time_point<file_clock, Duration>;   // C++20
300
301class steady_clock
302{
303public:
304    typedef nanoseconds                                   duration;
305    typedef duration::rep                                 rep;
306    typedef duration::period                              period;
307    typedef chrono::time_point<steady_clock, duration>    time_point;
308    static const bool is_steady =                         true; // constexpr in C++14
309
310    static time_point now() noexcept;
311};
312
313typedef steady_clock high_resolution_clock;
314
315// 25.7.8, local time           // C++20
316struct local_t {};
317template<class Duration>
318  using local_time  = time_point<local_t, Duration>;
319using local_seconds = local_time<seconds>;
320using local_days    = local_time<days>;
321
322// 25.7.9, time_point conversions template<class DestClock, class SourceClock>    // C++20
323struct clock_time_conversion;
324
325template<class DestClock, class SourceClock, class Duration>
326  auto clock_cast(const time_point<SourceClock, Duration>& t);
327
328// 25.8.2, class last_spec    // C++20
329struct last_spec;
330
331// 25.8.3, class day          // C++20
332
333class day;
334constexpr bool operator==(const day& x, const day& y) noexcept;
335constexpr bool operator!=(const day& x, const day& y) noexcept;
336constexpr bool operator< (const day& x, const day& y) noexcept;
337constexpr bool operator> (const day& x, const day& y) noexcept;
338constexpr bool operator<=(const day& x, const day& y) noexcept;
339constexpr bool operator>=(const day& x, const day& y) noexcept;
340constexpr day  operator+(const day&  x, const days& y) noexcept;
341constexpr day  operator+(const days& x, const day&  y) noexcept;
342constexpr day  operator-(const day&  x, const days& y) noexcept;
343constexpr days operator-(const day&  x, const day&  y) noexcept;
344
345// 25.8.4, class month    // C++20
346class month;
347constexpr bool operator==(const month& x, const month& y) noexcept;
348constexpr bool operator!=(const month& x, const month& y) noexcept;
349constexpr bool operator< (const month& x, const month& y) noexcept;
350constexpr bool operator> (const month& x, const month& y) noexcept;
351constexpr bool operator<=(const month& x, const month& y) noexcept;
352constexpr bool operator>=(const month& x, const month& y) noexcept;
353constexpr month  operator+(const month&  x, const months& y) noexcept;
354constexpr month  operator+(const months& x,  const month& y) noexcept;
355constexpr month  operator-(const month&  x, const months& y) noexcept;
356constexpr months operator-(const month&  x,  const month& y) noexcept;
357
358// 25.8.5, class year    // C++20
359class year;
360constexpr bool operator==(const year& x, const year& y) noexcept;
361constexpr bool operator!=(const year& x, const year& y) noexcept;
362constexpr bool operator< (const year& x, const year& y) noexcept;
363constexpr bool operator> (const year& x, const year& y) noexcept;
364constexpr bool operator<=(const year& x, const year& y) noexcept;
365constexpr bool operator>=(const year& x, const year& y) noexcept;
366constexpr year  operator+(const year&  x, const years& y) noexcept;
367constexpr year  operator+(const years& x, const year&  y) noexcept;
368constexpr year  operator-(const year&  x, const years& y) noexcept;
369constexpr years operator-(const year&  x, const year&  y) noexcept;
370
371// 25.8.6, class weekday    // C++20
372class weekday;
373
374constexpr bool operator==(const weekday& x, const weekday& y) noexcept;
375constexpr bool operator!=(const weekday& x, const weekday& y) noexcept;
376constexpr weekday operator+(const weekday& x, const days&    y) noexcept;
377constexpr weekday operator+(const days&    x, const weekday& y) noexcept;
378constexpr weekday operator-(const weekday& x, const days&    y) noexcept;
379constexpr days    operator-(const weekday& x, const weekday& y) noexcept;
380
381// 25.8.7, class weekday_indexed    // C++20
382
383class weekday_indexed;
384constexpr bool operator==(const weekday_indexed& x, const weekday_indexed& y) noexcept;
385constexpr bool operator!=(const weekday_indexed& x, const weekday_indexed& y) noexcept;
386
387// 25.8.8, class weekday_last    // C++20
388class weekday_last;
389
390constexpr bool operator==(const weekday_last& x, const weekday_last& y) noexcept;
391constexpr bool operator!=(const weekday_last& x, const weekday_last& y) noexcept;
392
393// 25.8.9, class month_day    // C++20
394class month_day;
395
396constexpr bool operator==(const month_day& x, const month_day& y) noexcept;
397constexpr bool operator!=(const month_day& x, const month_day& y) noexcept;
398constexpr bool operator< (const month_day& x, const month_day& y) noexcept;
399constexpr bool operator> (const month_day& x, const month_day& y) noexcept;
400constexpr bool operator<=(const month_day& x, const month_day& y) noexcept;
401constexpr bool operator>=(const month_day& x, const month_day& y) noexcept;
402
403
404// 25.8.10, class month_day_last    // C++20
405class month_day_last;
406
407constexpr bool operator==(const month_day_last& x, const month_day_last& y) noexcept;
408constexpr bool operator!=(const month_day_last& x, const month_day_last& y) noexcept;
409constexpr bool operator< (const month_day_last& x, const month_day_last& y) noexcept;
410constexpr bool operator> (const month_day_last& x, const month_day_last& y) noexcept;
411constexpr bool operator<=(const month_day_last& x, const month_day_last& y) noexcept;
412constexpr bool operator>=(const month_day_last& x, const month_day_last& y) noexcept;
413
414// 25.8.11, class month_weekday    // C++20
415class month_weekday;
416
417constexpr bool operator==(const month_weekday& x, const month_weekday& y) noexcept;
418constexpr bool operator!=(const month_weekday& x, const month_weekday& y) noexcept;
419
420// 25.8.12, class month_weekday_last    // C++20
421class month_weekday_last;
422
423constexpr bool operator==(const month_weekday_last& x, const month_weekday_last& y) noexcept;
424constexpr bool operator!=(const month_weekday_last& x, const month_weekday_last& y) noexcept;
425
426
427// 25.8.13, class year_month    // C++20
428class year_month;
429
430constexpr bool operator==(const year_month& x, const year_month& y) noexcept;
431constexpr bool operator!=(const year_month& x, const year_month& y) noexcept;
432constexpr bool operator< (const year_month& x, const year_month& y) noexcept;
433constexpr bool operator> (const year_month& x, const year_month& y) noexcept;
434constexpr bool operator<=(const year_month& x, const year_month& y) noexcept;
435constexpr bool operator>=(const year_month& x, const year_month& y) noexcept;
436
437constexpr year_month operator+(const year_month& ym, const months& dm) noexcept;
438constexpr year_month operator+(const months& dm, const year_month& ym) noexcept;
439constexpr year_month operator-(const year_month& ym, const months& dm) noexcept;
440constexpr months operator-(const year_month& x, const year_month& y) noexcept;
441constexpr year_month operator+(const year_month& ym, const years& dy) noexcept;
442constexpr year_month operator+(const years& dy, const year_month& ym) noexcept;
443constexpr year_month operator-(const year_month& ym, const years& dy) noexcept;
444
445// 25.8.14, class year_month_day class    // C++20
446year_month_day;
447
448constexpr bool operator==(const year_month_day& x, const year_month_day& y) noexcept;
449constexpr bool operator!=(const year_month_day& x, const year_month_day& y) noexcept;
450constexpr bool operator< (const year_month_day& x, const year_month_day& y) noexcept;
451constexpr bool operator> (const year_month_day& x, const year_month_day& y) noexcept;
452constexpr bool operator<=(const year_month_day& x, const year_month_day& y) noexcept;
453constexpr bool operator>=(const year_month_day& x, const year_month_day& y) noexcept;
454
455constexpr year_month_day operator+(const year_month_day& ymd, const months& dm) noexcept;
456constexpr year_month_day operator+(const months& dm, const year_month_day& ymd) noexcept;
457constexpr year_month_day operator+(const year_month_day& ymd, const years& dy) noexcept;
458constexpr year_month_day operator+(const years& dy, const year_month_day& ymd) noexcept;
459constexpr year_month_day operator-(const year_month_day& ymd, const months& dm) noexcept;
460constexpr year_month_day operator-(const year_month_day& ymd, const years& dy) noexcept;
461
462
463// 25.8.15, class year_month_day_last    // C++20
464class year_month_day_last;
465
466constexpr bool operator==(const year_month_day_last& x,
467                          const year_month_day_last& y) noexcept;
468constexpr bool operator!=(const year_month_day_last& x,
469                          const year_month_day_last& y) noexcept;
470constexpr bool operator< (const year_month_day_last& x,
471                          const year_month_day_last& y) noexcept;
472constexpr bool operator> (const year_month_day_last& x,
473                          const year_month_day_last& y) noexcept;
474constexpr bool operator<=(const year_month_day_last& x,
475                          const year_month_day_last& y) noexcept;
476constexpr bool operator>=(const year_month_day_last& x,
477                          const year_month_day_last& y) noexcept;
478
479constexpr year_month_day_last
480  operator+(const year_month_day_last& ymdl, const months& dm) noexcept;
481constexpr year_month_day_last
482  operator+(const months& dm, const year_month_day_last& ymdl) noexcept;
483constexpr year_month_day_last
484  operator+(const year_month_day_last& ymdl, const years& dy) noexcept;
485constexpr year_month_day_last
486  operator+(const years& dy, const year_month_day_last& ymdl) noexcept;
487constexpr year_month_day_last
488  operator-(const year_month_day_last& ymdl, const months& dm) noexcept;
489constexpr year_month_day_last
490  operator-(const year_month_day_last& ymdl, const years& dy) noexcept;
491
492// 25.8.16, class year_month_weekday    // C++20
493class year_month_weekday;
494
495constexpr bool operator==(const year_month_weekday& x,
496                          const year_month_weekday& y) noexcept;
497constexpr bool operator!=(const year_month_weekday& x,
498                          const year_month_weekday& y) noexcept;
499
500constexpr year_month_weekday
501  operator+(const year_month_weekday& ymwd, const months& dm) noexcept;
502constexpr year_month_weekday
503  operator+(const months& dm, const year_month_weekday& ymwd) noexcept;
504constexpr year_month_weekday
505  operator+(const year_month_weekday& ymwd, const years& dy) noexcept;
506constexpr year_month_weekday
507  operator+(const years& dy, const year_month_weekday& ymwd) noexcept;
508constexpr year_month_weekday
509  operator-(const year_month_weekday& ymwd, const months& dm) noexcept;
510constexpr year_month_weekday
511  operator-(const year_month_weekday& ymwd, const years& dy) noexcept;
512
513// 25.8.17, class year_month_weekday_last    // C++20
514class year_month_weekday_last;
515
516constexpr bool operator==(const year_month_weekday_last& x,
517                          const year_month_weekday_last& y) noexcept;
518constexpr bool operator!=(const year_month_weekday_last& x,
519                          const year_month_weekday_last& y) noexcept;
520constexpr year_month_weekday_last
521  operator+(const year_month_weekday_last& ymwdl, const months& dm) noexcept;
522constexpr year_month_weekday_last
523  operator+(const months& dm, const year_month_weekday_last& ymwdl) noexcept;
524constexpr year_month_weekday_last
525  operator+(const year_month_weekday_last& ymwdl, const years& dy) noexcept;
526constexpr year_month_weekday_last
527  operator+(const years& dy, const year_month_weekday_last& ymwdl) noexcept;
528constexpr year_month_weekday_last
529  operator-(const year_month_weekday_last& ymwdl, const months& dm) noexcept;
530constexpr year_month_weekday_last
531  operator-(const year_month_weekday_last& ymwdl, const years& dy) noexcept;
532
533// 25.8.18, civil calendar conventional syntax operators    // C++20
534constexpr year_month
535  operator/(const year& y, const month& m) noexcept;
536constexpr year_month
537  operator/(const year& y, int m) noexcept;
538constexpr month_day
539  operator/(const month& m, const day& d) noexcept;
540constexpr month_day
541  operator/(const month& m, int d) noexcept;
542constexpr month_day
543  operator/(int m, const day& d) noexcept;
544constexpr month_day
545  operator/(const day& d, const month& m) noexcept;
546constexpr month_day
547  operator/(const day& d, int m) noexcept;
548constexpr month_day_last
549  operator/(const month& m, last_spec) noexcept;
550constexpr month_day_last
551  operator/(int m, last_spec) noexcept;
552constexpr month_day_last
553  operator/(last_spec, const month& m) noexcept;
554constexpr month_day_last
555  operator/(last_spec, int m) noexcept;
556constexpr month_weekday
557  operator/(const month& m, const weekday_indexed& wdi) noexcept;
558constexpr month_weekday
559  operator/(int m, const weekday_indexed& wdi) noexcept;
560constexpr month_weekday
561  operator/(const weekday_indexed& wdi, const month& m) noexcept;
562constexpr month_weekday
563  operator/(const weekday_indexed& wdi, int m) noexcept;
564constexpr month_weekday_last
565  operator/(const month& m, const weekday_last& wdl) noexcept;
566constexpr month_weekday_last
567  operator/(int m, const weekday_last& wdl) noexcept;
568constexpr month_weekday_last
569  operator/(const weekday_last& wdl, const month& m) noexcept;
570constexpr month_weekday_last
571  operator/(const weekday_last& wdl, int m) noexcept;
572constexpr year_month_day
573  operator/(const year_month& ym, const day& d) noexcept;
574constexpr year_month_day
575  operator/(const year_month& ym, int d) noexcept;
576constexpr year_month_day
577  operator/(const year& y, const month_day& md) noexcept;
578constexpr year_month_day
579  operator/(int y, const month_day& md) noexcept;
580constexpr year_month_day
581  operator/(const month_day& md, const year& y) noexcept;
582constexpr year_month_day
583  operator/(const month_day& md, int y) noexcept;
584constexpr year_month_day_last
585  operator/(const year_month& ym, last_spec) noexcept;
586constexpr year_month_day_last
587  operator/(const year& y, const month_day_last& mdl) noexcept;
588constexpr year_month_day_last
589  operator/(int y, const month_day_last& mdl) noexcept;
590constexpr year_month_day_last
591  operator/(const month_day_last& mdl, const year& y) noexcept;
592constexpr year_month_day_last
593  operator/(const month_day_last& mdl, int y) noexcept;
594constexpr year_month_weekday
595  operator/(const year_month& ym, const weekday_indexed& wdi) noexcept;
596constexpr year_month_weekday
597  operator/(const year& y, const month_weekday& mwd) noexcept;
598constexpr year_month_weekday
599  operator/(int y, const month_weekday& mwd) noexcept;
600constexpr year_month_weekday
601  operator/(const month_weekday& mwd, const year& y) noexcept;
602constexpr year_month_weekday
603  operator/(const month_weekday& mwd, int y) noexcept;
604constexpr year_month_weekday_last
605  operator/(const year_month& ym, const weekday_last& wdl) noexcept;
606constexpr year_month_weekday_last
607  operator/(const year& y, const month_weekday_last& mwdl) noexcept;
608constexpr year_month_weekday_last
609  operator/(int y, const month_weekday_last& mwdl) noexcept;
610constexpr year_month_weekday_last
611  operator/(const month_weekday_last& mwdl, const year& y) noexcept;
612constexpr year_month_weekday_last
613  operator/(const month_weekday_last& mwdl, int y) noexcept;
614
615// 26.9, class template hh_mm_ss
616template <class Duration>
617class hh_mm_ss
618{
619    bool            is_neg; // exposition only
620    chrono::hours   h;      // exposition only
621    chrono::minutes m;      // exposition only
622    chrono::seconds s;      // exposition only
623    precision       ss;     // exposition only
624
625public:
626    static unsigned constexpr fractional_width = see below;
627    using precision                            = see below;
628
629    constexpr hh_mm_ss() noexcept : hh_mm_ss{Duration::zero()} {}
630    constexpr explicit hh_mm_ss(Duration d) noexcept;
631
632    constexpr bool is_negative() const noexcept;
633    constexpr chrono::hours hours() const noexcept;
634    constexpr chrono::minutes minutes() const noexcept;
635    constexpr chrono::seconds seconds() const noexcept;
636    constexpr precision subseconds() const noexcept;
637
638    constexpr explicit operator  precision()   const noexcept;
639    constexpr          precision to_duration() const noexcept;
640};
641
642template <class charT, class traits, class Duration>
643  basic_ostream<charT, traits>&
644    operator<<(basic_ostream<charT, traits>& os, hh_mm_ss<Duration> const& hms);
645
646// 26.10, 12/24 hour functions
647constexpr bool is_am(hours const& h) noexcept;
648constexpr bool is_pm(hours const& h) noexcept;
649constexpr hours make12(const hours& h) noexcept;
650constexpr hours make24(const hours& h, bool is_pm) noexcept;
651
652
653// 25.10.2, time zone database     // C++20
654struct tzdb;
655class tzdb_list;
656
657// 25.10.2.3, time zone database access    // C++20
658const tzdb& get_tzdb();
659tzdb_list& get_tzdb_list();
660const time_zone* locate_zone(string_view tz_name);
661const time_zone* current_zone();
662
663// 25.10.2.4, remote time zone database support    // C++20
664const tzdb& reload_tzdb();
665string remote_version();
666
667// 25.10.3, exception classes    // C++20
668class nonexistent_local_time;
669class ambiguous_local_time;
670
671// 25.10.4, information classes    // C++20
672struct sys_info;
673struct local_info;
674
675// 25.10.5, class time_zone    // C++20
676enum class choose {earliest, latest};
677class time_zone;
678bool operator==(const time_zone& x, const time_zone& y) noexcept;
679bool operator!=(const time_zone& x, const time_zone& y) noexcept;
680bool operator<(const time_zone& x, const time_zone& y) noexcept;
681bool operator>(const time_zone& x, const time_zone& y) noexcept;
682bool operator<=(const time_zone& x, const time_zone& y) noexcept;
683bool operator>=(const time_zone& x, const time_zone& y) noexcept;
684
685// 25.10.6, class template zoned_traits    // C++20
686template<class T> struct zoned_traits;
687
688// 25.10.7, class template zoned_time    // C++20
689template<class Duration, class TimeZonePtr = const time_zone*> class zoned_time;
690using zoned_seconds = zoned_time<seconds>;
691
692template<class Duration1, class Duration2, class TimeZonePtr>
693  bool operator==(const zoned_time<Duration1, TimeZonePtr>& x,
694                  const zoned_time<Duration2, TimeZonePtr>& y);
695template<class Duration1, class Duration2, class TimeZonePtr>
696  bool operator!=(const zoned_time<Duration1, TimeZonePtr>& x,
697                  const zoned_time<Duration2, TimeZonePtr>& y);
698
699// 25.10.8, leap second support    // C++20
700class leap;
701
702bool operator==(const leap& x, const leap& y);
703bool operator!=(const leap& x, const leap& y);
704bool operator< (const leap& x, const leap& y);
705bool operator> (const leap& x, const leap& y);
706bool operator<=(const leap& x, const leap& y);
707bool operator>=(const leap& x, const leap& y);
708template<class Duration>
709  bool operator==(const leap& x, const sys_time<Duration>& y);
710template<class Duration>
711  bool operator==(const sys_time<Duration>& x, const leap& y);
712template<class Duration>
713  bool operator!=(const leap& x, const sys_time<Duration>& y);
714template<class Duration>
715  bool operator!=(const sys_time<Duration>& x, const leap& y);
716template<class Duration>
717  bool operator< (const leap& x, const sys_time<Duration>& y);
718template<class Duration>
719  bool operator< (const sys_time<Duration>& x, const leap& y);
720template<class Duration>
721  bool operator> (const leap& x, const sys_time<Duration>& y);
722template<class Duration>
723  bool operator> (const sys_time<Duration>& x, const leap& y);
724template<class Duration>
725  bool operator<=(const leap& x, const sys_time<Duration>& y);
726template<class Duration>
727  bool operator<=(const sys_time<Duration>& x, const leap& y);
728template<class Duration>
729  bool operator>=(const leap& x, const sys_time<Duration>& y);
730template<class Duration>
731  bool operator>=(const sys_time<Duration>& x, const leap& y);
732
733// 25.10.9, class link    // C++20
734class link;
735bool operator==(const link& x, const link& y);
736bool operator!=(const link& x, const link& y);
737bool operator< (const link& x, const link& y);
738bool operator> (const link& x, const link& y);
739bool operator<=(const link& x, const link& y);
740bool operator>=(const link& x, const link& y);
741
742// 25.11, formatting    // C++20
743template<class charT, class Streamable>
744  basic_string<charT>
745    format(const charT* fmt, const Streamable& s);
746
747template<class charT, class Streamable>
748  basic_string<charT>
749    format(const locale& loc, const charT* fmt, const Streamable& s);
750
751template<class charT, class traits, class Alloc, class Streamable>
752  basic_string<charT, traits, Alloc>
753    format(const basic_string<charT, traits, Alloc>& fmt, const Streamable& s);
754
755template<class charT, class traits, class Alloc, class Streamable>
756  basic_string<charT, traits, Alloc>
757    format(const locale& loc, const basic_string<charT, traits, Alloc>& fmt,
758           const Streamable& s);
759
760// 25.12, parsing    // C++20
761template<class charT, class traits, class Alloc, class Parsable>
762unspecified
763    parse(const basic_string<charT, traits, Alloc>& format, Parsable& tp);
764
765template<class charT, class traits, class Alloc, class Parsable>
766unspecified
767    parse(const basic_string<charT, traits, Alloc>& format, Parsable& tp,
768          basic_string<charT, traits, Alloc>& abbrev);
769
770template<class charT, class traits, class Alloc, class Parsable>
771unspecified
772    parse(const basic_string<charT, traits, Alloc>& format, Parsable& tp,
773          minutes& offset);
774
775template<class charT, class traits, class Alloc, class Parsable>
776unspecified
777    parse(const basic_string<charT, traits, Alloc>& format, Parsable& tp,
778          basic_string<charT, traits, Alloc>& abbrev, minutes& offset);
779
780// calendrical constants
781inline constexpr last_spec                              last{};       // C++20
782inline constexpr chrono::weekday                        Sunday{0};    // C++20
783inline constexpr chrono::weekday                        Monday{1};    // C++20
784inline constexpr chrono::weekday                        Tuesday{2};   // C++20
785inline constexpr chrono::weekday                        Wednesday{3}; // C++20
786inline constexpr chrono::weekday                        Thursday{4};  // C++20
787inline constexpr chrono::weekday                        Friday{5};    // C++20
788inline constexpr chrono::weekday                        Saturday{6};  // C++20
789
790inline constexpr chrono::month                          January{1};   // C++20
791inline constexpr chrono::month                          February{2};  // C++20
792inline constexpr chrono::month                          March{3};     // C++20
793inline constexpr chrono::month                          April{4};     // C++20
794inline constexpr chrono::month                          May{5};       // C++20
795inline constexpr chrono::month                          June{6};      // C++20
796inline constexpr chrono::month                          July{7};      // C++20
797inline constexpr chrono::month                          August{8};    // C++20
798inline constexpr chrono::month                          September{9}; // C++20
799inline constexpr chrono::month                          October{10};  // C++20
800inline constexpr chrono::month                          November{11}; // C++20
801inline constexpr chrono::month                          December{12}; // C++20
802}  // chrono
803
804inline namespace literals {
805  inline namespace chrono_literals {
806constexpr chrono::hours                                 operator ""h(unsigned long long); // C++14
807constexpr chrono::duration<unspecified , ratio<3600,1>> operator ""h(long double); // C++14
808constexpr chrono::minutes                               operator ""min(unsigned long long); // C++14
809constexpr chrono::duration<unspecified , ratio<60,1>>   operator ""min(long double); // C++14
810constexpr chrono::seconds                               operator ""s(unsigned long long); // C++14
811constexpr chrono::duration<unspecified >                operator ""s(long double); // C++14
812constexpr chrono::milliseconds                          operator ""ms(unsigned long long); // C++14
813constexpr chrono::duration<unspecified , milli>         operator ""ms(long double); // C++14
814constexpr chrono::microseconds                          operator ""us(unsigned long long); // C++14
815constexpr chrono::duration<unspecified , micro>         operator ""us(long double); // C++14
816constexpr chrono::nanoseconds                           operator ""ns(unsigned long long); // C++14
817constexpr chrono::duration<unspecified , nano>          operator ""ns(long double); // C++14
818constexpr chrono::day                                   operator ""d(unsigned long long d) noexcept; // C++20
819constexpr chrono::year                                  operator ""y(unsigned long long y) noexcept; // C++20
820}  // chrono_literals
821}  // literals
822
823}  // std
824*/
825
826#include <__config>
827#include <__availability>
828#include <ctime>
829#include <type_traits>
830#include <ratio>
831#include <limits>
832#include <version>
833
834#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
835#pragma GCC system_header
836#endif
837
838_LIBCPP_PUSH_MACROS
839#include <__undef_macros>
840
841#ifndef _LIBCPP_CXX03_LANG
842_LIBCPP_BEGIN_NAMESPACE_FILESYSTEM
843struct _FilesystemClock;
844_LIBCPP_END_NAMESPACE_FILESYSTEM
845#endif // !_LIBCPP_CXX03_LANG
846
847_LIBCPP_BEGIN_NAMESPACE_STD
848
849namespace chrono
850{
851
852template <class _Rep, class _Period = ratio<1> > class _LIBCPP_TEMPLATE_VIS duration;
853
854template <class _Tp>
855struct __is_duration : false_type {};
856
857template <class _Rep, class _Period>
858struct __is_duration<duration<_Rep, _Period> > : true_type  {};
859
860template <class _Rep, class _Period>
861struct __is_duration<const duration<_Rep, _Period> > : true_type  {};
862
863template <class _Rep, class _Period>
864struct __is_duration<volatile duration<_Rep, _Period> > : true_type  {};
865
866template <class _Rep, class _Period>
867struct __is_duration<const volatile duration<_Rep, _Period> > : true_type  {};
868
869} // chrono
870
871template <class _Rep1, class _Period1, class _Rep2, class _Period2>
872struct _LIBCPP_TEMPLATE_VIS common_type<chrono::duration<_Rep1, _Period1>,
873                                         chrono::duration<_Rep2, _Period2> >
874{
875    typedef chrono::duration<typename common_type<_Rep1, _Rep2>::type,
876                             typename __ratio_gcd<_Period1, _Period2>::type> type;
877};
878
879namespace chrono {
880
881// duration_cast
882
883template <class _FromDuration, class _ToDuration,
884          class _Period = typename ratio_divide<typename _FromDuration::period, typename _ToDuration::period>::type,
885          bool = _Period::num == 1,
886          bool = _Period::den == 1>
887struct __duration_cast;
888
889template <class _FromDuration, class _ToDuration, class _Period>
890struct __duration_cast<_FromDuration, _ToDuration, _Period, true, true>
891{
892    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
893    _ToDuration operator()(const _FromDuration& __fd) const
894    {
895        return _ToDuration(static_cast<typename _ToDuration::rep>(__fd.count()));
896    }
897};
898
899template <class _FromDuration, class _ToDuration, class _Period>
900struct __duration_cast<_FromDuration, _ToDuration, _Period, true, false>
901{
902    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
903    _ToDuration operator()(const _FromDuration& __fd) const
904    {
905        typedef typename common_type<typename _ToDuration::rep, typename _FromDuration::rep, intmax_t>::type _Ct;
906        return _ToDuration(static_cast<typename _ToDuration::rep>(
907                           static_cast<_Ct>(__fd.count()) / static_cast<_Ct>(_Period::den)));
908    }
909};
910
911template <class _FromDuration, class _ToDuration, class _Period>
912struct __duration_cast<_FromDuration, _ToDuration, _Period, false, true>
913{
914    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
915    _ToDuration operator()(const _FromDuration& __fd) const
916    {
917        typedef typename common_type<typename _ToDuration::rep, typename _FromDuration::rep, intmax_t>::type _Ct;
918        return _ToDuration(static_cast<typename _ToDuration::rep>(
919                           static_cast<_Ct>(__fd.count()) * static_cast<_Ct>(_Period::num)));
920    }
921};
922
923template <class _FromDuration, class _ToDuration, class _Period>
924struct __duration_cast<_FromDuration, _ToDuration, _Period, false, false>
925{
926    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
927    _ToDuration operator()(const _FromDuration& __fd) const
928    {
929        typedef typename common_type<typename _ToDuration::rep, typename _FromDuration::rep, intmax_t>::type _Ct;
930        return _ToDuration(static_cast<typename _ToDuration::rep>(
931                           static_cast<_Ct>(__fd.count()) * static_cast<_Ct>(_Period::num)
932                                                          / static_cast<_Ct>(_Period::den)));
933    }
934};
935
936template <class _ToDuration, class _Rep, class _Period>
937inline _LIBCPP_INLINE_VISIBILITY
938_LIBCPP_CONSTEXPR
939typename enable_if
940<
941    __is_duration<_ToDuration>::value,
942    _ToDuration
943>::type
944duration_cast(const duration<_Rep, _Period>& __fd)
945{
946    return __duration_cast<duration<_Rep, _Period>, _ToDuration>()(__fd);
947}
948
949template <class _Rep>
950struct _LIBCPP_TEMPLATE_VIS treat_as_floating_point : is_floating_point<_Rep> {};
951
952#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
953template <class _Rep>
954_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool treat_as_floating_point_v
955    = treat_as_floating_point<_Rep>::value;
956#endif
957
958template <class _Rep>
959struct _LIBCPP_TEMPLATE_VIS duration_values
960{
961public:
962    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR _Rep zero() _NOEXCEPT {return _Rep(0);}
963    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR _Rep max()  _NOEXCEPT {return numeric_limits<_Rep>::max();}
964    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR _Rep min()  _NOEXCEPT {return numeric_limits<_Rep>::lowest();}
965};
966
967#if _LIBCPP_STD_VER > 14
968template <class _ToDuration, class _Rep, class _Period>
969inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
970typename enable_if
971<
972    __is_duration<_ToDuration>::value,
973    _ToDuration
974>::type
975floor(const duration<_Rep, _Period>& __d)
976{
977    _ToDuration __t = duration_cast<_ToDuration>(__d);
978    if (__t > __d)
979        __t = __t - _ToDuration{1};
980    return __t;
981}
982
983template <class _ToDuration, class _Rep, class _Period>
984inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
985typename enable_if
986<
987    __is_duration<_ToDuration>::value,
988    _ToDuration
989>::type
990ceil(const duration<_Rep, _Period>& __d)
991{
992    _ToDuration __t = duration_cast<_ToDuration>(__d);
993    if (__t < __d)
994        __t = __t + _ToDuration{1};
995    return __t;
996}
997
998template <class _ToDuration, class _Rep, class _Period>
999inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1000typename enable_if
1001<
1002    __is_duration<_ToDuration>::value,
1003    _ToDuration
1004>::type
1005round(const duration<_Rep, _Period>& __d)
1006{
1007    _ToDuration __lower = floor<_ToDuration>(__d);
1008    _ToDuration __upper = __lower + _ToDuration{1};
1009    auto __lowerDiff = __d - __lower;
1010    auto __upperDiff = __upper - __d;
1011    if (__lowerDiff < __upperDiff)
1012        return __lower;
1013    if (__lowerDiff > __upperDiff)
1014        return __upper;
1015    return __lower.count() & 1 ? __upper : __lower;
1016}
1017#endif
1018
1019// duration
1020
1021template <class _Rep, class _Period>
1022class _LIBCPP_TEMPLATE_VIS duration
1023{
1024    static_assert(!__is_duration<_Rep>::value, "A duration representation can not be a duration");
1025    static_assert(__is_ratio<_Period>::value, "Second template parameter of duration must be a std::ratio");
1026    static_assert(_Period::num > 0, "duration period must be positive");
1027
1028    template <class _R1, class _R2>
1029    struct __no_overflow
1030    {
1031    private:
1032        static const intmax_t __gcd_n1_n2 = __static_gcd<_R1::num, _R2::num>::value;
1033        static const intmax_t __gcd_d1_d2 = __static_gcd<_R1::den, _R2::den>::value;
1034        static const intmax_t __n1 = _R1::num / __gcd_n1_n2;
1035        static const intmax_t __d1 = _R1::den / __gcd_d1_d2;
1036        static const intmax_t __n2 = _R2::num / __gcd_n1_n2;
1037        static const intmax_t __d2 = _R2::den / __gcd_d1_d2;
1038        static const intmax_t max = -((intmax_t(1) << (sizeof(intmax_t) * CHAR_BIT - 1)) + 1);
1039
1040        template <intmax_t _Xp, intmax_t _Yp, bool __overflow>
1041        struct __mul    // __overflow == false
1042        {
1043            static const intmax_t value = _Xp * _Yp;
1044        };
1045
1046        template <intmax_t _Xp, intmax_t _Yp>
1047        struct __mul<_Xp, _Yp, true>
1048        {
1049            static const intmax_t value = 1;
1050        };
1051
1052    public:
1053        static const bool value = (__n1 <= max / __d2) && (__n2 <= max / __d1);
1054        typedef ratio<__mul<__n1, __d2, !value>::value,
1055                      __mul<__n2, __d1, !value>::value> type;
1056    };
1057
1058public:
1059    typedef _Rep rep;
1060    typedef typename _Period::type period;
1061private:
1062    rep __rep_;
1063public:
1064
1065    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1066#ifndef _LIBCPP_CXX03_LANG
1067        duration() = default;
1068#else
1069        duration() {}
1070#endif
1071
1072    template <class _Rep2>
1073        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1074        explicit duration(const _Rep2& __r,
1075            typename enable_if
1076            <
1077               is_convertible<_Rep2, rep>::value &&
1078               (treat_as_floating_point<rep>::value ||
1079               !treat_as_floating_point<_Rep2>::value)
1080            >::type* = nullptr)
1081                : __rep_(__r) {}
1082
1083    // conversions
1084    template <class _Rep2, class _Period2>
1085        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1086        duration(const duration<_Rep2, _Period2>& __d,
1087            typename enable_if
1088            <
1089                __no_overflow<_Period2, period>::value && (
1090                treat_as_floating_point<rep>::value ||
1091                (__no_overflow<_Period2, period>::type::den == 1 &&
1092                 !treat_as_floating_point<_Rep2>::value))
1093            >::type* = nullptr)
1094                : __rep_(_VSTD::chrono::duration_cast<duration>(__d).count()) {}
1095
1096    // observer
1097
1098    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR rep count() const {return __rep_;}
1099
1100    // arithmetic
1101
1102    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR typename common_type<duration>::type operator+() const {return typename common_type<duration>::type(*this);}
1103    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR typename common_type<duration>::type operator-() const {return typename common_type<duration>::type(-__rep_);}
1104    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration& operator++()      {++__rep_; return *this;}
1105    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration  operator++(int)   {return duration(__rep_++);}
1106    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration& operator--()      {--__rep_; return *this;}
1107    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration  operator--(int)   {return duration(__rep_--);}
1108
1109    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration& operator+=(const duration& __d) {__rep_ += __d.count(); return *this;}
1110    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration& operator-=(const duration& __d) {__rep_ -= __d.count(); return *this;}
1111
1112    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration& operator*=(const rep& rhs) {__rep_ *= rhs; return *this;}
1113    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration& operator/=(const rep& rhs) {__rep_ /= rhs; return *this;}
1114    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration& operator%=(const rep& rhs) {__rep_ %= rhs; return *this;}
1115    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration& operator%=(const duration& rhs) {__rep_ %= rhs.count(); return *this;}
1116
1117    // special values
1118
1119    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR duration zero() _NOEXCEPT {return duration(duration_values<rep>::zero());}
1120    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR duration min()  _NOEXCEPT {return duration(duration_values<rep>::min());}
1121    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR duration max()  _NOEXCEPT {return duration(duration_values<rep>::max());}
1122};
1123
1124typedef duration<long long,         nano> nanoseconds;
1125typedef duration<long long,        micro> microseconds;
1126typedef duration<long long,        milli> milliseconds;
1127typedef duration<long long              > seconds;
1128typedef duration<     long, ratio<  60> > minutes;
1129typedef duration<     long, ratio<3600> > hours;
1130#if _LIBCPP_STD_VER > 17
1131typedef duration<     int, ratio_multiply<ratio<24>, hours::period>>         days;
1132typedef duration<     int, ratio_multiply<ratio<7>,   days::period>>         weeks;
1133typedef duration<     int, ratio_multiply<ratio<146097, 400>, days::period>> years;
1134typedef duration<     int, ratio_divide<years::period, ratio<12>>>           months;
1135#endif
1136// Duration ==
1137
1138template <class _LhsDuration, class _RhsDuration>
1139struct __duration_eq
1140{
1141    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1142    bool operator()(const _LhsDuration& __lhs, const _RhsDuration& __rhs) const
1143        {
1144            typedef typename common_type<_LhsDuration, _RhsDuration>::type _Ct;
1145            return _Ct(__lhs).count() == _Ct(__rhs).count();
1146        }
1147};
1148
1149template <class _LhsDuration>
1150struct __duration_eq<_LhsDuration, _LhsDuration>
1151{
1152    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1153    bool operator()(const _LhsDuration& __lhs, const _LhsDuration& __rhs) const
1154        {return __lhs.count() == __rhs.count();}
1155};
1156
1157template <class _Rep1, class _Period1, class _Rep2, class _Period2>
1158inline _LIBCPP_INLINE_VISIBILITY
1159_LIBCPP_CONSTEXPR
1160bool
1161operator==(const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
1162{
1163    return __duration_eq<duration<_Rep1, _Period1>, duration<_Rep2, _Period2> >()(__lhs, __rhs);
1164}
1165
1166// Duration !=
1167
1168template <class _Rep1, class _Period1, class _Rep2, class _Period2>
1169inline _LIBCPP_INLINE_VISIBILITY
1170_LIBCPP_CONSTEXPR
1171bool
1172operator!=(const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
1173{
1174    return !(__lhs == __rhs);
1175}
1176
1177// Duration <
1178
1179template <class _LhsDuration, class _RhsDuration>
1180struct __duration_lt
1181{
1182    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1183    bool operator()(const _LhsDuration& __lhs, const _RhsDuration& __rhs) const
1184        {
1185            typedef typename common_type<_LhsDuration, _RhsDuration>::type _Ct;
1186            return _Ct(__lhs).count() < _Ct(__rhs).count();
1187        }
1188};
1189
1190template <class _LhsDuration>
1191struct __duration_lt<_LhsDuration, _LhsDuration>
1192{
1193    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1194    bool operator()(const _LhsDuration& __lhs, const _LhsDuration& __rhs) const
1195        {return __lhs.count() < __rhs.count();}
1196};
1197
1198template <class _Rep1, class _Period1, class _Rep2, class _Period2>
1199inline _LIBCPP_INLINE_VISIBILITY
1200_LIBCPP_CONSTEXPR
1201bool
1202operator< (const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
1203{
1204    return __duration_lt<duration<_Rep1, _Period1>, duration<_Rep2, _Period2> >()(__lhs, __rhs);
1205}
1206
1207// Duration >
1208
1209template <class _Rep1, class _Period1, class _Rep2, class _Period2>
1210inline _LIBCPP_INLINE_VISIBILITY
1211_LIBCPP_CONSTEXPR
1212bool
1213operator> (const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
1214{
1215    return __rhs < __lhs;
1216}
1217
1218// Duration <=
1219
1220template <class _Rep1, class _Period1, class _Rep2, class _Period2>
1221inline _LIBCPP_INLINE_VISIBILITY
1222_LIBCPP_CONSTEXPR
1223bool
1224operator<=(const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
1225{
1226    return !(__rhs < __lhs);
1227}
1228
1229// Duration >=
1230
1231template <class _Rep1, class _Period1, class _Rep2, class _Period2>
1232inline _LIBCPP_INLINE_VISIBILITY
1233_LIBCPP_CONSTEXPR
1234bool
1235operator>=(const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
1236{
1237    return !(__lhs < __rhs);
1238}
1239
1240// Duration +
1241
1242template <class _Rep1, class _Period1, class _Rep2, class _Period2>
1243inline _LIBCPP_INLINE_VISIBILITY
1244_LIBCPP_CONSTEXPR
1245typename common_type<duration<_Rep1, _Period1>, duration<_Rep2, _Period2> >::type
1246operator+(const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
1247{
1248    typedef typename common_type<duration<_Rep1, _Period1>, duration<_Rep2, _Period2> >::type _Cd;
1249    return _Cd(_Cd(__lhs).count() + _Cd(__rhs).count());
1250}
1251
1252// Duration -
1253
1254template <class _Rep1, class _Period1, class _Rep2, class _Period2>
1255inline _LIBCPP_INLINE_VISIBILITY
1256_LIBCPP_CONSTEXPR
1257typename common_type<duration<_Rep1, _Period1>, duration<_Rep2, _Period2> >::type
1258operator-(const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
1259{
1260    typedef typename common_type<duration<_Rep1, _Period1>, duration<_Rep2, _Period2> >::type _Cd;
1261    return _Cd(_Cd(__lhs).count() - _Cd(__rhs).count());
1262}
1263
1264// Duration *
1265
1266template <class _Rep1, class _Period, class _Rep2>
1267inline _LIBCPP_INLINE_VISIBILITY
1268_LIBCPP_CONSTEXPR
1269typename enable_if
1270<
1271    is_convertible<_Rep2, typename common_type<_Rep1, _Rep2>::type>::value,
1272    duration<typename common_type<_Rep1, _Rep2>::type, _Period>
1273>::type
1274operator*(const duration<_Rep1, _Period>& __d, const _Rep2& __s)
1275{
1276    typedef typename common_type<_Rep1, _Rep2>::type _Cr;
1277    typedef duration<_Cr, _Period> _Cd;
1278    return _Cd(_Cd(__d).count() * static_cast<_Cr>(__s));
1279}
1280
1281template <class _Rep1, class _Period, class _Rep2>
1282inline _LIBCPP_INLINE_VISIBILITY
1283_LIBCPP_CONSTEXPR
1284typename enable_if
1285<
1286    is_convertible<_Rep1, typename common_type<_Rep1, _Rep2>::type>::value,
1287    duration<typename common_type<_Rep1, _Rep2>::type, _Period>
1288>::type
1289operator*(const _Rep1& __s, const duration<_Rep2, _Period>& __d)
1290{
1291    return __d * __s;
1292}
1293
1294// Duration /
1295
1296template <class _Rep1, class _Period, class _Rep2>
1297inline _LIBCPP_INLINE_VISIBILITY
1298_LIBCPP_CONSTEXPR
1299typename enable_if
1300<
1301    !__is_duration<_Rep2>::value &&
1302      is_convertible<_Rep2, typename common_type<_Rep1, _Rep2>::type>::value,
1303    duration<typename common_type<_Rep1, _Rep2>::type, _Period>
1304>::type
1305operator/(const duration<_Rep1, _Period>& __d, const _Rep2& __s)
1306{
1307    typedef typename common_type<_Rep1, _Rep2>::type _Cr;
1308    typedef duration<_Cr, _Period> _Cd;
1309    return _Cd(_Cd(__d).count() / static_cast<_Cr>(__s));
1310}
1311
1312template <class _Rep1, class _Period1, class _Rep2, class _Period2>
1313inline _LIBCPP_INLINE_VISIBILITY
1314_LIBCPP_CONSTEXPR
1315typename common_type<_Rep1, _Rep2>::type
1316operator/(const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
1317{
1318    typedef typename common_type<duration<_Rep1, _Period1>, duration<_Rep2, _Period2> >::type _Ct;
1319    return _Ct(__lhs).count() / _Ct(__rhs).count();
1320}
1321
1322// Duration %
1323
1324template <class _Rep1, class _Period, class _Rep2>
1325inline _LIBCPP_INLINE_VISIBILITY
1326_LIBCPP_CONSTEXPR
1327typename enable_if
1328<
1329    !__is_duration<_Rep2>::value &&
1330      is_convertible<_Rep2, typename common_type<_Rep1, _Rep2>::type>::value,
1331    duration<typename common_type<_Rep1, _Rep2>::type, _Period>
1332>::type
1333operator%(const duration<_Rep1, _Period>& __d, const _Rep2& __s)
1334{
1335    typedef typename common_type<_Rep1, _Rep2>::type _Cr;
1336    typedef duration<_Cr, _Period> _Cd;
1337    return _Cd(_Cd(__d).count() % static_cast<_Cr>(__s));
1338}
1339
1340template <class _Rep1, class _Period1, class _Rep2, class _Period2>
1341inline _LIBCPP_INLINE_VISIBILITY
1342_LIBCPP_CONSTEXPR
1343typename common_type<duration<_Rep1, _Period1>, duration<_Rep2, _Period2> >::type
1344operator%(const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
1345{
1346    typedef typename common_type<_Rep1, _Rep2>::type _Cr;
1347    typedef typename common_type<duration<_Rep1, _Period1>, duration<_Rep2, _Period2> >::type _Cd;
1348    return _Cd(static_cast<_Cr>(_Cd(__lhs).count()) % static_cast<_Cr>(_Cd(__rhs).count()));
1349}
1350
1351//////////////////////////////////////////////////////////
1352///////////////////// time_point /////////////////////////
1353//////////////////////////////////////////////////////////
1354
1355template <class _Clock, class _Duration = typename _Clock::duration>
1356class _LIBCPP_TEMPLATE_VIS time_point
1357{
1358    static_assert(__is_duration<_Duration>::value,
1359                  "Second template parameter of time_point must be a std::chrono::duration");
1360public:
1361    typedef _Clock                    clock;
1362    typedef _Duration                 duration;
1363    typedef typename duration::rep    rep;
1364    typedef typename duration::period period;
1365private:
1366    duration __d_;
1367
1368public:
1369    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 time_point() : __d_(duration::zero()) {}
1370    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 explicit time_point(const duration& __d) : __d_(__d) {}
1371
1372    // conversions
1373    template <class _Duration2>
1374    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1375    time_point(const time_point<clock, _Duration2>& t,
1376        typename enable_if
1377        <
1378            is_convertible<_Duration2, duration>::value
1379        >::type* = nullptr)
1380            : __d_(t.time_since_epoch()) {}
1381
1382    // observer
1383
1384    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 duration time_since_epoch() const {return __d_;}
1385
1386    // arithmetic
1387
1388    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 time_point& operator+=(const duration& __d) {__d_ += __d; return *this;}
1389    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 time_point& operator-=(const duration& __d) {__d_ -= __d; return *this;}
1390
1391    // special values
1392
1393    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR time_point min() _NOEXCEPT {return time_point(duration::min());}
1394    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR time_point max() _NOEXCEPT {return time_point(duration::max());}
1395};
1396
1397} // chrono
1398
1399template <class _Clock, class _Duration1, class _Duration2>
1400struct _LIBCPP_TEMPLATE_VIS common_type<chrono::time_point<_Clock, _Duration1>,
1401                                         chrono::time_point<_Clock, _Duration2> >
1402{
1403    typedef chrono::time_point<_Clock, typename common_type<_Duration1, _Duration2>::type> type;
1404};
1405
1406namespace chrono {
1407
1408template <class _ToDuration, class _Clock, class _Duration>
1409inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1410time_point<_Clock, _ToDuration>
1411time_point_cast(const time_point<_Clock, _Duration>& __t)
1412{
1413    return time_point<_Clock, _ToDuration>(_VSTD::chrono::duration_cast<_ToDuration>(__t.time_since_epoch()));
1414}
1415
1416#if _LIBCPP_STD_VER > 14
1417template <class _ToDuration, class _Clock, class _Duration>
1418inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1419typename enable_if
1420<
1421    __is_duration<_ToDuration>::value,
1422    time_point<_Clock, _ToDuration>
1423>::type
1424floor(const time_point<_Clock, _Duration>& __t)
1425{
1426    return time_point<_Clock, _ToDuration>{floor<_ToDuration>(__t.time_since_epoch())};
1427}
1428
1429template <class _ToDuration, class _Clock, class _Duration>
1430inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1431typename enable_if
1432<
1433    __is_duration<_ToDuration>::value,
1434    time_point<_Clock, _ToDuration>
1435>::type
1436ceil(const time_point<_Clock, _Duration>& __t)
1437{
1438    return time_point<_Clock, _ToDuration>{ceil<_ToDuration>(__t.time_since_epoch())};
1439}
1440
1441template <class _ToDuration, class _Clock, class _Duration>
1442inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1443typename enable_if
1444<
1445    __is_duration<_ToDuration>::value,
1446    time_point<_Clock, _ToDuration>
1447>::type
1448round(const time_point<_Clock, _Duration>& __t)
1449{
1450    return time_point<_Clock, _ToDuration>{round<_ToDuration>(__t.time_since_epoch())};
1451}
1452
1453template <class _Rep, class _Period>
1454inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1455typename enable_if
1456<
1457    numeric_limits<_Rep>::is_signed,
1458    duration<_Rep, _Period>
1459>::type
1460abs(duration<_Rep, _Period> __d)
1461{
1462    return __d >= __d.zero() ? +__d : -__d;
1463}
1464#endif
1465
1466// time_point ==
1467
1468template <class _Clock, class _Duration1, class _Duration2>
1469inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1470bool
1471operator==(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
1472{
1473    return __lhs.time_since_epoch() == __rhs.time_since_epoch();
1474}
1475
1476// time_point !=
1477
1478template <class _Clock, class _Duration1, class _Duration2>
1479inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1480bool
1481operator!=(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
1482{
1483    return !(__lhs == __rhs);
1484}
1485
1486// time_point <
1487
1488template <class _Clock, class _Duration1, class _Duration2>
1489inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1490bool
1491operator<(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
1492{
1493    return __lhs.time_since_epoch() < __rhs.time_since_epoch();
1494}
1495
1496// time_point >
1497
1498template <class _Clock, class _Duration1, class _Duration2>
1499inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1500bool
1501operator>(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
1502{
1503    return __rhs < __lhs;
1504}
1505
1506// time_point <=
1507
1508template <class _Clock, class _Duration1, class _Duration2>
1509inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1510bool
1511operator<=(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
1512{
1513    return !(__rhs < __lhs);
1514}
1515
1516// time_point >=
1517
1518template <class _Clock, class _Duration1, class _Duration2>
1519inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1520bool
1521operator>=(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
1522{
1523    return !(__lhs < __rhs);
1524}
1525
1526// time_point operator+(time_point x, duration y);
1527
1528template <class _Clock, class _Duration1, class _Rep2, class _Period2>
1529inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1530time_point<_Clock, typename common_type<_Duration1, duration<_Rep2, _Period2> >::type>
1531operator+(const time_point<_Clock, _Duration1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
1532{
1533    typedef time_point<_Clock, typename common_type<_Duration1, duration<_Rep2, _Period2> >::type> _Tr;
1534    return _Tr (__lhs.time_since_epoch() + __rhs);
1535}
1536
1537// time_point operator+(duration x, time_point y);
1538
1539template <class _Rep1, class _Period1, class _Clock, class _Duration2>
1540inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1541time_point<_Clock, typename common_type<duration<_Rep1, _Period1>, _Duration2>::type>
1542operator+(const duration<_Rep1, _Period1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
1543{
1544    return __rhs + __lhs;
1545}
1546
1547// time_point operator-(time_point x, duration y);
1548
1549template <class _Clock, class _Duration1, class _Rep2, class _Period2>
1550inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1551time_point<_Clock, typename common_type<_Duration1, duration<_Rep2, _Period2> >::type>
1552operator-(const time_point<_Clock, _Duration1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
1553{
1554    typedef time_point<_Clock, typename common_type<_Duration1, duration<_Rep2, _Period2> >::type> _Ret;
1555    return _Ret(__lhs.time_since_epoch() -__rhs);
1556}
1557
1558// duration operator-(time_point x, time_point y);
1559
1560template <class _Clock, class _Duration1, class _Duration2>
1561inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1562typename common_type<_Duration1, _Duration2>::type
1563operator-(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
1564{
1565    return __lhs.time_since_epoch() - __rhs.time_since_epoch();
1566}
1567
1568//////////////////////////////////////////////////////////
1569/////////////////////// clocks ///////////////////////////
1570//////////////////////////////////////////////////////////
1571
1572class _LIBCPP_TYPE_VIS system_clock
1573{
1574public:
1575    typedef microseconds                     duration;
1576    typedef duration::rep                    rep;
1577    typedef duration::period                 period;
1578    typedef chrono::time_point<system_clock> time_point;
1579    static _LIBCPP_CONSTEXPR_AFTER_CXX11 const bool is_steady = false;
1580
1581    static time_point now() _NOEXCEPT;
1582    static time_t     to_time_t  (const time_point& __t) _NOEXCEPT;
1583    static time_point from_time_t(time_t __t) _NOEXCEPT;
1584};
1585
1586#ifndef _LIBCPP_HAS_NO_MONOTONIC_CLOCK
1587class _LIBCPP_TYPE_VIS steady_clock
1588{
1589public:
1590    typedef nanoseconds                                   duration;
1591    typedef duration::rep                                 rep;
1592    typedef duration::period                              period;
1593    typedef chrono::time_point<steady_clock, duration>    time_point;
1594    static _LIBCPP_CONSTEXPR_AFTER_CXX11 const bool is_steady = true;
1595
1596    static time_point now() _NOEXCEPT;
1597};
1598
1599typedef steady_clock high_resolution_clock;
1600#else
1601typedef system_clock high_resolution_clock;
1602#endif
1603
1604#if _LIBCPP_STD_VER > 17
1605// [time.clock.file], type file_clock
1606using file_clock = _VSTD_FS::_FilesystemClock;
1607
1608template<class _Duration>
1609using file_time = time_point<file_clock, _Duration>;
1610
1611
1612template <class _Duration>
1613using sys_time    = time_point<system_clock, _Duration>;
1614using sys_seconds = sys_time<seconds>;
1615using sys_days    = sys_time<days>;
1616
1617struct local_t {};
1618template<class Duration>
1619using local_time  = time_point<local_t, Duration>;
1620using local_seconds = local_time<seconds>;
1621using local_days    = local_time<days>;
1622
1623
1624struct last_spec { explicit last_spec() = default; };
1625
1626class day {
1627private:
1628    unsigned char __d;
1629public:
1630    day() = default;
1631    explicit inline constexpr day(unsigned __val) noexcept : __d(static_cast<unsigned char>(__val)) {}
1632    inline constexpr day& operator++()    noexcept { ++__d; return *this; }
1633    inline constexpr day  operator++(int) noexcept { day __tmp = *this; ++(*this); return __tmp; }
1634    inline constexpr day& operator--()    noexcept { --__d; return *this; }
1635    inline constexpr day  operator--(int) noexcept { day __tmp = *this; --(*this); return __tmp; }
1636           constexpr day& operator+=(const days& __dd) noexcept;
1637           constexpr day& operator-=(const days& __dd) noexcept;
1638    explicit inline constexpr operator unsigned() const noexcept { return __d; }
1639    inline constexpr bool ok() const noexcept { return __d >= 1 && __d <= 31; }
1640  };
1641
1642
1643inline constexpr
1644bool operator==(const day& __lhs, const day& __rhs) noexcept
1645{ return static_cast<unsigned>(__lhs) == static_cast<unsigned>(__rhs); }
1646
1647inline constexpr
1648bool operator!=(const day& __lhs, const day& __rhs) noexcept
1649{ return !(__lhs == __rhs); }
1650
1651inline constexpr
1652bool operator< (const day& __lhs, const day& __rhs) noexcept
1653{ return static_cast<unsigned>(__lhs) <  static_cast<unsigned>(__rhs); }
1654
1655inline constexpr
1656bool operator> (const day& __lhs, const day& __rhs) noexcept
1657{ return __rhs < __lhs; }
1658
1659inline constexpr
1660bool operator<=(const day& __lhs, const day& __rhs) noexcept
1661{ return !(__rhs < __lhs);}
1662
1663inline constexpr
1664bool operator>=(const day& __lhs, const day& __rhs) noexcept
1665{ return !(__lhs < __rhs); }
1666
1667inline constexpr
1668day operator+ (const day& __lhs, const days& __rhs) noexcept
1669{ return day(static_cast<unsigned>(__lhs) + __rhs.count()); }
1670
1671inline constexpr
1672day operator+ (const days& __lhs, const day& __rhs) noexcept
1673{ return __rhs + __lhs; }
1674
1675inline constexpr
1676day operator- (const day& __lhs, const days& __rhs) noexcept
1677{ return __lhs + -__rhs; }
1678
1679inline constexpr
1680days operator-(const day& __lhs, const day& __rhs) noexcept
1681{ return days(static_cast<int>(static_cast<unsigned>(__lhs)) -
1682              static_cast<int>(static_cast<unsigned>(__rhs))); }
1683
1684inline constexpr day& day::operator+=(const days& __dd) noexcept
1685{ *this = *this + __dd; return *this; }
1686
1687inline constexpr day& day::operator-=(const days& __dd) noexcept
1688{ *this = *this - __dd; return *this; }
1689
1690
1691class month {
1692private:
1693    unsigned char __m;
1694public:
1695    month() = default;
1696    explicit inline constexpr month(unsigned __val) noexcept : __m(static_cast<unsigned char>(__val)) {}
1697    inline constexpr month& operator++()    noexcept { ++__m; return *this; }
1698    inline constexpr month  operator++(int) noexcept { month __tmp = *this; ++(*this); return __tmp; }
1699    inline constexpr month& operator--()    noexcept { --__m; return *this; }
1700    inline constexpr month  operator--(int) noexcept { month __tmp = *this; --(*this); return __tmp; }
1701           constexpr month& operator+=(const months& __m1) noexcept;
1702           constexpr month& operator-=(const months& __m1) noexcept;
1703    explicit inline constexpr operator unsigned() const noexcept { return __m; }
1704    inline constexpr bool ok() const noexcept { return __m >= 1 && __m <= 12; }
1705};
1706
1707
1708inline constexpr
1709bool operator==(const month& __lhs, const month& __rhs) noexcept
1710{ return static_cast<unsigned>(__lhs) == static_cast<unsigned>(__rhs); }
1711
1712inline constexpr
1713bool operator!=(const month& __lhs, const month& __rhs) noexcept
1714{ return !(__lhs == __rhs); }
1715
1716inline constexpr
1717bool operator< (const month& __lhs, const month& __rhs) noexcept
1718{ return static_cast<unsigned>(__lhs)  < static_cast<unsigned>(__rhs); }
1719
1720inline constexpr
1721bool operator> (const month& __lhs, const month& __rhs) noexcept
1722{ return __rhs < __lhs; }
1723
1724inline constexpr
1725bool operator<=(const month& __lhs, const month& __rhs) noexcept
1726{ return !(__rhs < __lhs); }
1727
1728inline constexpr
1729bool operator>=(const month& __lhs, const month& __rhs) noexcept
1730{ return !(__lhs < __rhs); }
1731
1732inline constexpr
1733month operator+ (const month& __lhs, const months& __rhs) noexcept
1734{
1735    auto const __mu = static_cast<long long>(static_cast<unsigned>(__lhs)) + (__rhs.count() - 1);
1736    auto const __yr = (__mu >= 0 ? __mu : __mu - 11) / 12;
1737    return month{static_cast<unsigned>(__mu - __yr * 12 + 1)};
1738}
1739
1740inline constexpr
1741month operator+ (const months& __lhs, const month& __rhs) noexcept
1742{ return __rhs + __lhs; }
1743
1744inline constexpr
1745month operator- (const month& __lhs, const months& __rhs) noexcept
1746{ return __lhs + -__rhs; }
1747
1748inline constexpr
1749months operator-(const month& __lhs, const month& __rhs) noexcept
1750{
1751    auto const __dm = static_cast<unsigned>(__lhs) - static_cast<unsigned>(__rhs);
1752    return months(__dm <= 11 ? __dm : __dm + 12);
1753}
1754
1755inline constexpr month& month::operator+=(const months& __dm) noexcept
1756{ *this = *this + __dm; return *this; }
1757
1758inline constexpr month& month::operator-=(const months& __dm) noexcept
1759{ *this = *this - __dm; return *this; }
1760
1761
1762class year {
1763private:
1764    short __y;
1765public:
1766    year() = default;
1767    explicit inline constexpr year(int __val) noexcept : __y(static_cast<short>(__val)) {}
1768
1769    inline constexpr year& operator++()    noexcept { ++__y; return *this; }
1770    inline constexpr year  operator++(int) noexcept { year __tmp = *this; ++(*this); return __tmp; }
1771    inline constexpr year& operator--()    noexcept { --__y; return *this; }
1772    inline constexpr year  operator--(int) noexcept { year __tmp = *this; --(*this); return __tmp; }
1773           constexpr year& operator+=(const years& __dy) noexcept;
1774           constexpr year& operator-=(const years& __dy) noexcept;
1775    inline constexpr year operator+() const noexcept { return *this; }
1776    inline constexpr year operator-() const noexcept { return year{-__y}; }
1777
1778    inline constexpr bool is_leap() const noexcept { return __y % 4 == 0 && (__y % 100 != 0 || __y % 400 == 0); }
1779    explicit inline constexpr operator int() const noexcept { return __y; }
1780           constexpr bool ok() const noexcept;
1781    static inline constexpr year min() noexcept { return year{-32767}; }
1782    static inline constexpr year max() noexcept { return year{ 32767}; }
1783};
1784
1785
1786inline constexpr
1787bool operator==(const year& __lhs, const year& __rhs) noexcept
1788{ return static_cast<int>(__lhs) == static_cast<int>(__rhs); }
1789
1790inline constexpr
1791bool operator!=(const year& __lhs, const year& __rhs) noexcept
1792{ return !(__lhs == __rhs); }
1793
1794inline constexpr
1795bool operator< (const year& __lhs, const year& __rhs) noexcept
1796{ return static_cast<int>(__lhs)  < static_cast<int>(__rhs); }
1797
1798inline constexpr
1799bool operator> (const year& __lhs, const year& __rhs) noexcept
1800{ return __rhs < __lhs; }
1801
1802inline constexpr
1803bool operator<=(const year& __lhs, const year& __rhs) noexcept
1804{ return !(__rhs < __lhs); }
1805
1806inline constexpr
1807bool operator>=(const year& __lhs, const year& __rhs) noexcept
1808{ return !(__lhs < __rhs); }
1809
1810inline constexpr
1811year operator+ (const year& __lhs, const years& __rhs) noexcept
1812{ return year(static_cast<int>(__lhs) + __rhs.count()); }
1813
1814inline constexpr
1815year operator+ (const years& __lhs, const year& __rhs) noexcept
1816{ return __rhs + __lhs; }
1817
1818inline constexpr
1819year operator- (const year& __lhs, const years& __rhs) noexcept
1820{ return __lhs + -__rhs; }
1821
1822inline constexpr
1823years operator-(const year& __lhs, const year& __rhs) noexcept
1824{ return years{static_cast<int>(__lhs) - static_cast<int>(__rhs)}; }
1825
1826
1827inline constexpr year& year::operator+=(const years& __dy) noexcept
1828{ *this = *this + __dy; return *this; }
1829
1830inline constexpr year& year::operator-=(const years& __dy) noexcept
1831{ *this = *this - __dy; return *this; }
1832
1833inline constexpr bool year::ok() const noexcept
1834{ return static_cast<int>(min()) <= __y && __y <= static_cast<int>(max()); }
1835
1836class weekday_indexed;
1837class weekday_last;
1838
1839class weekday {
1840private:
1841    unsigned char __wd;
1842public:
1843  weekday() = default;
1844  inline explicit constexpr weekday(unsigned __val) noexcept : __wd(static_cast<unsigned char>(__val == 7 ? 0 : __val)) {}
1845  inline constexpr          weekday(const sys_days& __sysd) noexcept
1846          : __wd(__weekday_from_days(__sysd.time_since_epoch().count())) {}
1847  inline explicit constexpr weekday(const local_days& __locd) noexcept
1848          : __wd(__weekday_from_days(__locd.time_since_epoch().count())) {}
1849
1850  inline constexpr weekday& operator++()    noexcept { __wd = (__wd == 6 ? 0 : __wd + 1); return *this; }
1851  inline constexpr weekday  operator++(int) noexcept { weekday __tmp = *this; ++(*this); return __tmp; }
1852  inline constexpr weekday& operator--()    noexcept { __wd = (__wd == 0 ? 6 : __wd - 1); return *this; }
1853  inline constexpr weekday  operator--(int) noexcept { weekday __tmp = *this; --(*this); return __tmp; }
1854         constexpr weekday& operator+=(const days& __dd) noexcept;
1855         constexpr weekday& operator-=(const days& __dd) noexcept;
1856  inline constexpr unsigned c_encoding()   const noexcept { return __wd; }
1857  inline constexpr unsigned iso_encoding() const noexcept { return __wd == 0u ? 7 : __wd; }
1858  inline constexpr bool ok() const noexcept { return __wd <= 6; }
1859         constexpr weekday_indexed operator[](unsigned __index) const noexcept;
1860         constexpr weekday_last    operator[](last_spec) const noexcept;
1861
1862  // TODO: Make private?
1863  static constexpr unsigned char __weekday_from_days(int __days) noexcept;
1864};
1865
1866
1867// https://howardhinnant.github.io/date_algorithms.html#weekday_from_days
1868inline constexpr
1869unsigned char weekday::__weekday_from_days(int __days) noexcept
1870{
1871    return static_cast<unsigned char>(
1872              static_cast<unsigned>(__days >= -4 ? (__days+4) % 7 : (__days+5) % 7 + 6)
1873           );
1874}
1875
1876inline constexpr
1877bool operator==(const weekday& __lhs, const weekday& __rhs) noexcept
1878{ return __lhs.c_encoding() == __rhs.c_encoding(); }
1879
1880inline constexpr
1881bool operator!=(const weekday& __lhs, const weekday& __rhs) noexcept
1882{ return !(__lhs == __rhs); }
1883
1884inline constexpr
1885bool operator< (const weekday& __lhs, const weekday& __rhs) noexcept
1886{ return __lhs.c_encoding() < __rhs.c_encoding(); }
1887
1888inline constexpr
1889bool operator> (const weekday& __lhs, const weekday& __rhs) noexcept
1890{ return __rhs < __lhs; }
1891
1892inline constexpr
1893bool operator<=(const weekday& __lhs, const weekday& __rhs) noexcept
1894{ return !(__rhs < __lhs);}
1895
1896inline constexpr
1897bool operator>=(const weekday& __lhs, const weekday& __rhs) noexcept
1898{ return !(__lhs < __rhs); }
1899
1900constexpr weekday operator+(const weekday& __lhs, const days& __rhs) noexcept
1901{
1902    auto const __mu = static_cast<long long>(__lhs.c_encoding()) + __rhs.count();
1903    auto const __yr = (__mu >= 0 ? __mu : __mu - 6) / 7;
1904    return weekday{static_cast<unsigned>(__mu - __yr * 7)};
1905}
1906
1907constexpr weekday operator+(const days& __lhs, const weekday& __rhs) noexcept
1908{ return __rhs + __lhs; }
1909
1910constexpr weekday operator-(const weekday& __lhs, const days& __rhs) noexcept
1911{ return __lhs + -__rhs; }
1912
1913constexpr days operator-(const weekday& __lhs, const weekday& __rhs) noexcept
1914{
1915    const int __wdu = __lhs.c_encoding() - __rhs.c_encoding();
1916    const int __wk = (__wdu >= 0 ? __wdu : __wdu-6) / 7;
1917    return days{__wdu - __wk * 7};
1918}
1919
1920inline constexpr weekday& weekday::operator+=(const days& __dd) noexcept
1921{ *this = *this + __dd; return *this; }
1922
1923inline constexpr weekday& weekday::operator-=(const days& __dd) noexcept
1924{ *this = *this - __dd; return *this; }
1925
1926
1927class weekday_indexed {
1928private:
1929    _VSTD::chrono::weekday __wd;
1930    unsigned char          __idx;
1931public:
1932    weekday_indexed() = default;
1933    inline constexpr weekday_indexed(const _VSTD::chrono::weekday& __wdval, unsigned __idxval) noexcept
1934        : __wd{__wdval}, __idx(__idxval) {}
1935    inline constexpr _VSTD::chrono::weekday weekday() const noexcept { return __wd; }
1936    inline constexpr unsigned                 index() const noexcept { return __idx; }
1937    inline constexpr bool ok() const noexcept { return __wd.ok() && __idx >= 1 && __idx <= 5; }
1938};
1939
1940inline constexpr
1941bool operator==(const weekday_indexed& __lhs, const weekday_indexed& __rhs) noexcept
1942{ return __lhs.weekday() == __rhs.weekday() && __lhs.index() == __rhs.index(); }
1943
1944inline constexpr
1945bool operator!=(const weekday_indexed& __lhs, const weekday_indexed& __rhs) noexcept
1946{ return !(__lhs == __rhs); }
1947
1948
1949class weekday_last {
1950private:
1951    _VSTD::chrono::weekday __wd;
1952public:
1953    explicit constexpr weekday_last(const _VSTD::chrono::weekday& __val) noexcept
1954        : __wd{__val} {}
1955    constexpr _VSTD::chrono::weekday weekday() const noexcept { return __wd; }
1956    constexpr bool ok() const noexcept { return __wd.ok(); }
1957};
1958
1959inline constexpr
1960bool operator==(const weekday_last& __lhs, const weekday_last& __rhs) noexcept
1961{ return __lhs.weekday() == __rhs.weekday(); }
1962
1963inline constexpr
1964bool operator!=(const weekday_last& __lhs, const weekday_last& __rhs) noexcept
1965{ return !(__lhs == __rhs); }
1966
1967inline constexpr
1968weekday_indexed weekday::operator[](unsigned __index) const noexcept { return weekday_indexed{*this, __index}; }
1969
1970inline constexpr
1971weekday_last    weekday::operator[](last_spec) const noexcept { return weekday_last{*this}; }
1972
1973
1974inline constexpr last_spec last{};
1975inline constexpr weekday   Sunday{0};
1976inline constexpr weekday   Monday{1};
1977inline constexpr weekday   Tuesday{2};
1978inline constexpr weekday   Wednesday{3};
1979inline constexpr weekday   Thursday{4};
1980inline constexpr weekday   Friday{5};
1981inline constexpr weekday   Saturday{6};
1982
1983inline constexpr month January{1};
1984inline constexpr month February{2};
1985inline constexpr month March{3};
1986inline constexpr month April{4};
1987inline constexpr month May{5};
1988inline constexpr month June{6};
1989inline constexpr month July{7};
1990inline constexpr month August{8};
1991inline constexpr month September{9};
1992inline constexpr month October{10};
1993inline constexpr month November{11};
1994inline constexpr month December{12};
1995
1996
1997class month_day {
1998private:
1999   chrono::month __m;
2000   chrono::day   __d;
2001public:
2002    month_day() = default;
2003    constexpr month_day(const chrono::month& __mval, const chrono::day& __dval) noexcept
2004        : __m{__mval}, __d{__dval} {}
2005    inline constexpr chrono::month month() const noexcept { return __m; }
2006    inline constexpr chrono::day   day()   const noexcept { return __d; }
2007    constexpr bool ok() const noexcept;
2008};
2009
2010inline constexpr
2011bool month_day::ok() const noexcept
2012{
2013    if (!__m.ok()) return false;
2014    const unsigned __dval = static_cast<unsigned>(__d);
2015    if (__dval < 1 || __dval > 31) return false;
2016    if (__dval <= 29) return true;
2017//  Now we've got either 30 or 31
2018    const unsigned __mval = static_cast<unsigned>(__m);
2019    if (__mval == 2) return false;
2020    if (__mval == 4 || __mval == 6 || __mval == 9 || __mval == 11)
2021        return __dval == 30;
2022    return true;
2023}
2024
2025inline constexpr
2026bool operator==(const month_day& __lhs, const month_day& __rhs) noexcept
2027{ return __lhs.month() == __rhs.month() && __lhs.day() == __rhs.day(); }
2028
2029inline constexpr
2030bool operator!=(const month_day& __lhs, const month_day& __rhs) noexcept
2031{ return !(__lhs == __rhs); }
2032
2033inline constexpr
2034month_day operator/(const month& __lhs, const day& __rhs) noexcept
2035{ return month_day{__lhs, __rhs}; }
2036
2037constexpr
2038month_day operator/(const day& __lhs, const month& __rhs) noexcept
2039{ return __rhs / __lhs; }
2040
2041inline constexpr
2042month_day operator/(const month& __lhs, int __rhs) noexcept
2043{ return __lhs / day(__rhs); }
2044
2045constexpr
2046month_day operator/(int __lhs, const day& __rhs) noexcept
2047{ return month(__lhs) / __rhs; }
2048
2049constexpr
2050month_day operator/(const day& __lhs, int __rhs) noexcept
2051{ return month(__rhs) / __lhs; }
2052
2053
2054inline constexpr
2055bool operator< (const month_day& __lhs, const month_day& __rhs) noexcept
2056{ return __lhs.month() != __rhs.month() ? __lhs.month() < __rhs.month() : __lhs.day() < __rhs.day(); }
2057
2058inline constexpr
2059bool operator> (const month_day& __lhs, const month_day& __rhs) noexcept
2060{ return __rhs < __lhs; }
2061
2062inline constexpr
2063bool operator<=(const month_day& __lhs, const month_day& __rhs) noexcept
2064{ return !(__rhs < __lhs);}
2065
2066inline constexpr
2067bool operator>=(const month_day& __lhs, const month_day& __rhs) noexcept
2068{ return !(__lhs < __rhs); }
2069
2070
2071
2072class month_day_last {
2073private:
2074    chrono::month __m;
2075public:
2076    explicit constexpr month_day_last(const chrono::month& __val) noexcept
2077        : __m{__val} {}
2078    inline constexpr chrono::month month() const noexcept { return __m; }
2079    inline constexpr bool ok() const noexcept { return __m.ok(); }
2080};
2081
2082inline constexpr
2083bool operator==(const month_day_last& __lhs, const month_day_last& __rhs) noexcept
2084{ return __lhs.month() == __rhs.month(); }
2085
2086inline constexpr
2087bool operator!=(const month_day_last& __lhs, const month_day_last& __rhs) noexcept
2088{ return !(__lhs == __rhs); }
2089
2090inline constexpr
2091bool operator< (const month_day_last& __lhs, const month_day_last& __rhs) noexcept
2092{ return __lhs.month() < __rhs.month(); }
2093
2094inline constexpr
2095bool operator> (const month_day_last& __lhs, const month_day_last& __rhs) noexcept
2096{ return __rhs < __lhs; }
2097
2098inline constexpr
2099bool operator<=(const month_day_last& __lhs, const month_day_last& __rhs) noexcept
2100{ return !(__rhs < __lhs);}
2101
2102inline constexpr
2103bool operator>=(const month_day_last& __lhs, const month_day_last& __rhs) noexcept
2104{ return !(__lhs < __rhs); }
2105
2106inline constexpr
2107month_day_last operator/(const month& __lhs, last_spec) noexcept
2108{ return month_day_last{__lhs}; }
2109
2110inline constexpr
2111month_day_last operator/(last_spec, const month& __rhs) noexcept
2112{ return month_day_last{__rhs}; }
2113
2114inline constexpr
2115month_day_last operator/(int __lhs, last_spec) noexcept
2116{ return month_day_last{month(__lhs)}; }
2117
2118inline constexpr
2119month_day_last operator/(last_spec, int __rhs) noexcept
2120{ return month_day_last{month(__rhs)}; }
2121
2122
2123class month_weekday {
2124private:
2125    chrono::month __m;
2126    chrono::weekday_indexed __wdi;
2127public:
2128    month_weekday() = default;
2129    constexpr month_weekday(const chrono::month& __mval, const chrono::weekday_indexed& __wdival) noexcept
2130        : __m{__mval}, __wdi{__wdival} {}
2131    inline constexpr chrono::month                     month() const noexcept { return __m; }
2132    inline constexpr chrono::weekday_indexed weekday_indexed() const noexcept { return __wdi; }
2133    inline constexpr bool                                 ok() const noexcept { return __m.ok() && __wdi.ok(); }
2134};
2135
2136inline constexpr
2137bool operator==(const month_weekday& __lhs, const month_weekday& __rhs) noexcept
2138{ return __lhs.month() == __rhs.month() && __lhs.weekday_indexed() == __rhs.weekday_indexed(); }
2139
2140inline constexpr
2141bool operator!=(const month_weekday& __lhs, const month_weekday& __rhs) noexcept
2142{ return !(__lhs == __rhs); }
2143
2144inline constexpr
2145month_weekday operator/(const month& __lhs, const weekday_indexed& __rhs) noexcept
2146{ return month_weekday{__lhs, __rhs}; }
2147
2148inline constexpr
2149month_weekday operator/(int __lhs, const weekday_indexed& __rhs) noexcept
2150{ return month_weekday{month(__lhs), __rhs}; }
2151
2152inline constexpr
2153month_weekday operator/(const weekday_indexed& __lhs, const month& __rhs) noexcept
2154{ return month_weekday{__rhs, __lhs}; }
2155
2156inline constexpr
2157month_weekday operator/(const weekday_indexed& __lhs, int __rhs) noexcept
2158{ return month_weekday{month(__rhs), __lhs}; }
2159
2160
2161class month_weekday_last {
2162    chrono::month        __m;
2163    chrono::weekday_last __wdl;
2164  public:
2165    constexpr month_weekday_last(const chrono::month& __mval, const chrono::weekday_last& __wdlval) noexcept
2166        : __m{__mval}, __wdl{__wdlval} {}
2167    inline constexpr chrono::month               month() const noexcept { return __m; }
2168    inline constexpr chrono::weekday_last weekday_last() const noexcept { return __wdl; }
2169    inline constexpr bool                           ok() const noexcept { return __m.ok() && __wdl.ok(); }
2170};
2171
2172inline constexpr
2173bool operator==(const month_weekday_last& __lhs, const month_weekday_last& __rhs) noexcept
2174{ return __lhs.month() == __rhs.month() && __lhs.weekday_last() == __rhs.weekday_last(); }
2175
2176inline constexpr
2177bool operator!=(const month_weekday_last& __lhs, const month_weekday_last& __rhs) noexcept
2178{ return !(__lhs == __rhs); }
2179
2180
2181inline constexpr
2182month_weekday_last operator/(const month& __lhs, const weekday_last& __rhs) noexcept
2183{ return month_weekday_last{__lhs, __rhs}; }
2184
2185inline constexpr
2186month_weekday_last operator/(int __lhs, const weekday_last& __rhs) noexcept
2187{ return month_weekday_last{month(__lhs), __rhs}; }
2188
2189inline constexpr
2190month_weekday_last operator/(const weekday_last& __lhs, const month& __rhs) noexcept
2191{ return month_weekday_last{__rhs, __lhs}; }
2192
2193inline constexpr
2194month_weekday_last operator/(const weekday_last& __lhs, int __rhs) noexcept
2195{ return month_weekday_last{month(__rhs), __lhs}; }
2196
2197
2198class year_month {
2199    chrono::year  __y;
2200    chrono::month __m;
2201public:
2202    year_month() = default;
2203    constexpr year_month(const chrono::year& __yval, const chrono::month& __mval) noexcept
2204        : __y{__yval}, __m{__mval} {}
2205    inline constexpr chrono::year  year()  const noexcept { return __y; }
2206    inline constexpr chrono::month month() const noexcept { return __m; }
2207    inline constexpr year_month& operator+=(const months& __dm) noexcept { this->__m += __dm; return *this; }
2208    inline constexpr year_month& operator-=(const months& __dm) noexcept { this->__m -= __dm; return *this; }
2209    inline constexpr year_month& operator+=(const years& __dy)  noexcept { this->__y += __dy; return *this; }
2210    inline constexpr year_month& operator-=(const years& __dy)  noexcept { this->__y -= __dy; return *this; }
2211    inline constexpr bool ok() const noexcept { return __y.ok() && __m.ok(); }
2212};
2213
2214inline constexpr
2215year_month operator/(const year& __y, const month& __m) noexcept { return year_month{__y, __m}; }
2216
2217inline constexpr
2218year_month operator/(const year& __y, int __m) noexcept { return year_month{__y, month(__m)}; }
2219
2220inline constexpr
2221bool operator==(const year_month& __lhs, const year_month& __rhs) noexcept
2222{ return __lhs.year() == __rhs.year() && __lhs.month() == __rhs.month(); }
2223
2224inline constexpr
2225bool operator!=(const year_month& __lhs, const year_month& __rhs) noexcept
2226{ return !(__lhs == __rhs); }
2227
2228inline constexpr
2229bool operator< (const year_month& __lhs, const year_month& __rhs) noexcept
2230{ return __lhs.year() != __rhs.year() ? __lhs.year() < __rhs.year() : __lhs.month() < __rhs.month(); }
2231
2232inline constexpr
2233bool operator> (const year_month& __lhs, const year_month& __rhs) noexcept
2234{ return __rhs < __lhs; }
2235
2236inline constexpr
2237bool operator<=(const year_month& __lhs, const year_month& __rhs) noexcept
2238{ return !(__rhs < __lhs);}
2239
2240inline constexpr
2241bool operator>=(const year_month& __lhs, const year_month& __rhs) noexcept
2242{ return !(__lhs < __rhs); }
2243
2244constexpr year_month operator+(const year_month& __lhs, const months& __rhs) noexcept
2245{
2246    int __dmi = static_cast<int>(static_cast<unsigned>(__lhs.month())) - 1 + __rhs.count();
2247    const int __dy = (__dmi >= 0 ? __dmi : __dmi-11) / 12;
2248    __dmi = __dmi - __dy * 12 + 1;
2249    return (__lhs.year() + years(__dy)) / month(static_cast<unsigned>(__dmi));
2250}
2251
2252constexpr year_month operator+(const months& __lhs, const year_month& __rhs) noexcept
2253{ return __rhs + __lhs; }
2254
2255constexpr year_month operator+(const year_month& __lhs, const years& __rhs) noexcept
2256{ return (__lhs.year() + __rhs) / __lhs.month(); }
2257
2258constexpr year_month operator+(const years& __lhs, const year_month& __rhs) noexcept
2259{ return __rhs + __lhs; }
2260
2261constexpr months     operator-(const year_month& __lhs, const year_month& __rhs) noexcept
2262{ return (__lhs.year() - __rhs.year()) + months(static_cast<unsigned>(__lhs.month()) - static_cast<unsigned>(__rhs.month())); }
2263
2264constexpr year_month operator-(const year_month& __lhs, const months& __rhs) noexcept
2265{ return __lhs + -__rhs; }
2266
2267constexpr year_month operator-(const year_month& __lhs, const years& __rhs) noexcept
2268{ return __lhs + -__rhs; }
2269
2270class year_month_day_last;
2271
2272class year_month_day {
2273private:
2274    chrono::year  __y;
2275    chrono::month __m;
2276    chrono::day   __d;
2277public:
2278     year_month_day() = default;
2279     inline constexpr year_month_day(
2280            const chrono::year& __yval, const chrono::month& __mval, const chrono::day& __dval) noexcept
2281            : __y{__yval}, __m{__mval}, __d{__dval} {}
2282            constexpr year_month_day(const year_month_day_last& __ymdl) noexcept;
2283     inline constexpr year_month_day(const sys_days& __sysd) noexcept
2284            : year_month_day(__from_days(__sysd.time_since_epoch())) {}
2285     inline explicit constexpr year_month_day(const local_days& __locd) noexcept
2286            : year_month_day(__from_days(__locd.time_since_epoch())) {}
2287
2288            constexpr year_month_day& operator+=(const months& __dm) noexcept;
2289            constexpr year_month_day& operator-=(const months& __dm) noexcept;
2290            constexpr year_month_day& operator+=(const years& __dy)  noexcept;
2291            constexpr year_month_day& operator-=(const years& __dy)  noexcept;
2292
2293     inline constexpr chrono::year   year() const noexcept { return __y; }
2294     inline constexpr chrono::month month() const noexcept { return __m; }
2295     inline constexpr chrono::day     day() const noexcept { return __d; }
2296     inline constexpr operator   sys_days() const noexcept          { return   sys_days{__to_days()}; }
2297     inline explicit constexpr operator local_days() const noexcept { return local_days{__to_days()}; }
2298
2299            constexpr bool             ok() const noexcept;
2300
2301     static constexpr year_month_day __from_days(days __d) noexcept;
2302     constexpr days __to_days() const noexcept;
2303};
2304
2305
2306// https://howardhinnant.github.io/date_algorithms.html#civil_from_days
2307inline constexpr
2308year_month_day
2309year_month_day::__from_days(days __d) noexcept
2310{
2311    static_assert(std::numeric_limits<unsigned>::digits >= 18, "");
2312    static_assert(std::numeric_limits<int>::digits >= 20     , "");
2313    const int      __z = __d.count() + 719468;
2314    const int      __era = (__z >= 0 ? __z : __z - 146096) / 146097;
2315    const unsigned __doe = static_cast<unsigned>(__z - __era * 146097);              // [0, 146096]
2316    const unsigned __yoe = (__doe - __doe/1460 + __doe/36524 - __doe/146096) / 365;  // [0, 399]
2317    const int      __yr = static_cast<int>(__yoe) + __era * 400;
2318    const unsigned __doy = __doe - (365 * __yoe + __yoe/4 - __yoe/100);              // [0, 365]
2319    const unsigned __mp = (5 * __doy + 2)/153;                                       // [0, 11]
2320    const unsigned __dy = __doy - (153 * __mp + 2)/5 + 1;                            // [1, 31]
2321    const unsigned __mth = __mp + (__mp < 10 ? 3 : -9);                              // [1, 12]
2322    return year_month_day{chrono::year{__yr + (__mth <= 2)}, chrono::month{__mth}, chrono::day{__dy}};
2323}
2324
2325// https://howardhinnant.github.io/date_algorithms.html#days_from_civil
2326inline constexpr days year_month_day::__to_days() const noexcept
2327{
2328    static_assert(std::numeric_limits<unsigned>::digits >= 18, "");
2329    static_assert(std::numeric_limits<int>::digits >= 20     , "");
2330
2331    const int      __yr  = static_cast<int>(__y) - (__m <= February);
2332    const unsigned __mth = static_cast<unsigned>(__m);
2333    const unsigned __dy  = static_cast<unsigned>(__d);
2334
2335    const int      __era = (__yr >= 0 ? __yr : __yr - 399) / 400;
2336    const unsigned __yoe = static_cast<unsigned>(__yr - __era * 400);                // [0, 399]
2337    const unsigned __doy = (153 * (__mth + (__mth > 2 ? -3 : 9)) + 2) / 5 + __dy-1;  // [0, 365]
2338    const unsigned __doe = __yoe * 365 + __yoe/4 - __yoe/100 + __doy;                // [0, 146096]
2339    return days{__era * 146097 + static_cast<int>(__doe) - 719468};
2340}
2341
2342inline constexpr
2343bool operator==(const year_month_day& __lhs, const year_month_day& __rhs) noexcept
2344{ return __lhs.year() == __rhs.year() && __lhs.month() == __rhs.month() && __lhs.day() == __rhs.day(); }
2345
2346inline constexpr
2347bool operator!=(const year_month_day& __lhs, const year_month_day& __rhs) noexcept
2348{ return !(__lhs == __rhs); }
2349
2350inline constexpr
2351bool operator< (const year_month_day& __lhs, const year_month_day& __rhs) noexcept
2352{
2353    if (__lhs.year() < __rhs.year()) return true;
2354    if (__lhs.year() > __rhs.year()) return false;
2355    if (__lhs.month() < __rhs.month()) return true;
2356    if (__lhs.month() > __rhs.month()) return false;
2357    return __lhs.day() < __rhs.day();
2358}
2359
2360inline constexpr
2361bool operator> (const year_month_day& __lhs, const year_month_day& __rhs) noexcept
2362{ return __rhs < __lhs; }
2363
2364inline constexpr
2365bool operator<=(const year_month_day& __lhs, const year_month_day& __rhs) noexcept
2366{ return !(__rhs < __lhs);}
2367
2368inline constexpr
2369bool operator>=(const year_month_day& __lhs, const year_month_day& __rhs) noexcept
2370{ return !(__lhs < __rhs); }
2371
2372inline constexpr
2373year_month_day operator/(const year_month& __lhs, const day& __rhs) noexcept
2374{ return year_month_day{__lhs.year(), __lhs.month(), __rhs}; }
2375
2376inline constexpr
2377year_month_day operator/(const year_month& __lhs, int __rhs) noexcept
2378{ return __lhs / day(__rhs); }
2379
2380inline constexpr
2381year_month_day operator/(const year& __lhs, const month_day& __rhs) noexcept
2382{ return __lhs / __rhs.month() / __rhs.day(); }
2383
2384inline constexpr
2385year_month_day operator/(int __lhs, const month_day& __rhs) noexcept
2386{ return year(__lhs) / __rhs; }
2387
2388inline constexpr
2389year_month_day operator/(const month_day& __lhs, const year& __rhs) noexcept
2390{ return __rhs / __lhs; }
2391
2392inline constexpr
2393year_month_day operator/(const month_day& __lhs, int __rhs) noexcept
2394{ return year(__rhs) / __lhs; }
2395
2396
2397inline constexpr
2398year_month_day operator+(const year_month_day& __lhs, const months& __rhs) noexcept
2399{ return (__lhs.year()/__lhs.month() + __rhs)/__lhs.day(); }
2400
2401inline constexpr
2402year_month_day operator+(const months& __lhs, const year_month_day& __rhs) noexcept
2403{ return __rhs + __lhs; }
2404
2405inline constexpr
2406year_month_day operator-(const year_month_day& __lhs, const months& __rhs) noexcept
2407{ return __lhs + -__rhs; }
2408
2409inline constexpr
2410year_month_day operator+(const year_month_day& __lhs, const years& __rhs) noexcept
2411{ return (__lhs.year() + __rhs) / __lhs.month() / __lhs.day(); }
2412
2413inline constexpr
2414year_month_day operator+(const years& __lhs, const year_month_day& __rhs) noexcept
2415{ return __rhs + __lhs; }
2416
2417inline constexpr
2418year_month_day operator-(const year_month_day& __lhs, const years& __rhs) noexcept
2419{ return __lhs + -__rhs; }
2420
2421inline constexpr year_month_day& year_month_day::operator+=(const months& __dm) noexcept { *this = *this + __dm; return *this; }
2422inline constexpr year_month_day& year_month_day::operator-=(const months& __dm) noexcept { *this = *this - __dm; return *this; }
2423inline constexpr year_month_day& year_month_day::operator+=(const years& __dy)  noexcept { *this = *this + __dy; return *this; }
2424inline constexpr year_month_day& year_month_day::operator-=(const years& __dy)  noexcept { *this = *this - __dy; return *this; }
2425
2426class year_month_day_last {
2427private:
2428    chrono::year           __y;
2429    chrono::month_day_last __mdl;
2430public:
2431     constexpr year_month_day_last(const year& __yval, const month_day_last& __mdlval) noexcept
2432        : __y{__yval}, __mdl{__mdlval} {}
2433
2434     constexpr year_month_day_last& operator+=(const months& __m) noexcept;
2435     constexpr year_month_day_last& operator-=(const months& __m) noexcept;
2436     constexpr year_month_day_last& operator+=(const years& __y)  noexcept;
2437     constexpr year_month_day_last& operator-=(const years& __y)  noexcept;
2438
2439     inline constexpr chrono::year                     year() const noexcept { return __y; }
2440     inline constexpr chrono::month                   month() const noexcept { return __mdl.month(); }
2441     inline constexpr chrono::month_day_last month_day_last() const noexcept { return __mdl; }
2442            constexpr chrono::day                       day() const noexcept;
2443     inline constexpr operator                     sys_days() const noexcept { return   sys_days{year()/month()/day()}; }
2444     inline explicit constexpr operator          local_days() const noexcept { return local_days{year()/month()/day()}; }
2445     inline constexpr bool                               ok() const noexcept { return __y.ok() && __mdl.ok(); }
2446};
2447
2448inline constexpr
2449chrono::day year_month_day_last::day() const noexcept
2450{
2451    constexpr chrono::day __d[] =
2452    {
2453        chrono::day(31), chrono::day(28), chrono::day(31),
2454        chrono::day(30), chrono::day(31), chrono::day(30),
2455        chrono::day(31), chrono::day(31), chrono::day(30),
2456        chrono::day(31), chrono::day(30), chrono::day(31)
2457    };
2458    return (month() != February || !__y.is_leap()) && month().ok() ?
2459        __d[static_cast<unsigned>(month()) - 1] : chrono::day{29};
2460}
2461
2462inline constexpr
2463bool operator==(const year_month_day_last& __lhs, const year_month_day_last& __rhs) noexcept
2464{ return __lhs.year() == __rhs.year() && __lhs.month_day_last() == __rhs.month_day_last(); }
2465
2466inline constexpr
2467bool operator!=(const year_month_day_last& __lhs, const year_month_day_last& __rhs) noexcept
2468{ return !(__lhs == __rhs); }
2469
2470inline constexpr
2471bool operator< (const year_month_day_last& __lhs, const year_month_day_last& __rhs) noexcept
2472{
2473    if (__lhs.year() < __rhs.year()) return true;
2474    if (__lhs.year() > __rhs.year()) return false;
2475    return __lhs.month_day_last() < __rhs.month_day_last();
2476}
2477
2478inline constexpr
2479bool operator> (const year_month_day_last& __lhs, const year_month_day_last& __rhs) noexcept
2480{ return __rhs < __lhs; }
2481
2482inline constexpr
2483bool operator<=(const year_month_day_last& __lhs, const year_month_day_last& __rhs) noexcept
2484{ return !(__rhs < __lhs);}
2485
2486inline constexpr
2487bool operator>=(const year_month_day_last& __lhs, const year_month_day_last& __rhs) noexcept
2488{ return !(__lhs < __rhs); }
2489
2490inline constexpr year_month_day_last operator/(const year_month& __lhs, last_spec) noexcept
2491{ return year_month_day_last{__lhs.year(), month_day_last{__lhs.month()}}; }
2492
2493inline constexpr year_month_day_last operator/(const year& __lhs, const month_day_last& __rhs) noexcept
2494{ return year_month_day_last{__lhs, __rhs}; }
2495
2496inline constexpr year_month_day_last operator/(int __lhs, const month_day_last& __rhs) noexcept
2497{ return year_month_day_last{year{__lhs}, __rhs}; }
2498
2499inline constexpr year_month_day_last operator/(const month_day_last& __lhs, const year& __rhs) noexcept
2500{ return __rhs / __lhs; }
2501
2502inline constexpr year_month_day_last operator/(const month_day_last& __lhs, int __rhs) noexcept
2503{ return year{__rhs} / __lhs; }
2504
2505
2506inline constexpr
2507year_month_day_last operator+(const year_month_day_last& __lhs, const months& __rhs) noexcept
2508{ return (__lhs.year() / __lhs.month() + __rhs) / last; }
2509
2510inline constexpr
2511year_month_day_last operator+(const months& __lhs, const year_month_day_last& __rhs) noexcept
2512{ return __rhs + __lhs; }
2513
2514inline constexpr
2515year_month_day_last operator-(const year_month_day_last& __lhs, const months& __rhs) noexcept
2516{ return __lhs + (-__rhs); }
2517
2518inline constexpr
2519year_month_day_last operator+(const year_month_day_last& __lhs, const years& __rhs) noexcept
2520{ return year_month_day_last{__lhs.year() + __rhs, __lhs.month_day_last()}; }
2521
2522inline constexpr
2523year_month_day_last operator+(const years& __lhs, const year_month_day_last& __rhs) noexcept
2524{ return __rhs + __lhs; }
2525
2526inline constexpr
2527year_month_day_last operator-(const year_month_day_last& __lhs, const years& __rhs) noexcept
2528{ return __lhs + (-__rhs); }
2529
2530inline constexpr year_month_day_last& year_month_day_last::operator+=(const months& __dm) noexcept { *this = *this + __dm; return *this; }
2531inline constexpr year_month_day_last& year_month_day_last::operator-=(const months& __dm) noexcept { *this = *this - __dm; return *this; }
2532inline constexpr year_month_day_last& year_month_day_last::operator+=(const years& __dy)  noexcept { *this = *this + __dy; return *this; }
2533inline constexpr year_month_day_last& year_month_day_last::operator-=(const years& __dy)  noexcept { *this = *this - __dy; return *this; }
2534
2535inline constexpr year_month_day::year_month_day(const year_month_day_last& __ymdl) noexcept
2536    : __y{__ymdl.year()}, __m{__ymdl.month()}, __d{__ymdl.day()} {}
2537
2538inline constexpr bool year_month_day::ok() const noexcept
2539{
2540    if (!__y.ok() || !__m.ok()) return false;
2541    return chrono::day{1} <= __d && __d <= (__y / __m / last).day();
2542}
2543
2544class year_month_weekday {
2545    chrono::year            __y;
2546    chrono::month           __m;
2547    chrono::weekday_indexed __wdi;
2548public:
2549    year_month_weekday() = default;
2550    constexpr year_month_weekday(const chrono::year& __yval, const chrono::month& __mval,
2551                               const chrono::weekday_indexed& __wdival) noexcept
2552        : __y{__yval}, __m{__mval}, __wdi{__wdival} {}
2553    constexpr year_month_weekday(const sys_days& __sysd) noexcept
2554            : year_month_weekday(__from_days(__sysd.time_since_epoch())) {}
2555    inline explicit constexpr year_month_weekday(const local_days& __locd) noexcept
2556            : year_month_weekday(__from_days(__locd.time_since_epoch())) {}
2557    constexpr year_month_weekday& operator+=(const months& m) noexcept;
2558    constexpr year_month_weekday& operator-=(const months& m) noexcept;
2559    constexpr year_month_weekday& operator+=(const years& y)  noexcept;
2560    constexpr year_month_weekday& operator-=(const years& y)  noexcept;
2561
2562    inline constexpr chrono::year                       year() const noexcept { return __y; }
2563    inline constexpr chrono::month                     month() const noexcept { return __m; }
2564    inline constexpr chrono::weekday                 weekday() const noexcept { return __wdi.weekday(); }
2565    inline constexpr unsigned                          index() const noexcept { return __wdi.index(); }
2566    inline constexpr chrono::weekday_indexed weekday_indexed() const noexcept { return __wdi; }
2567
2568    inline constexpr                       operator sys_days() const noexcept { return   sys_days{__to_days()}; }
2569    inline explicit constexpr operator            local_days() const noexcept { return local_days{__to_days()}; }
2570    inline constexpr bool ok() const noexcept
2571    {
2572        if (!__y.ok() || !__m.ok() || !__wdi.ok()) return false;
2573        if (__wdi.index() <= 4) return true;
2574        auto __nth_weekday_day =
2575            __wdi.weekday() -
2576            chrono::weekday{static_cast<sys_days>(__y / __m / 1)} +
2577            days{(__wdi.index() - 1) * 7 + 1};
2578        return static_cast<unsigned>(__nth_weekday_day.count()) <=
2579               static_cast<unsigned>((__y / __m / last).day());
2580    }
2581
2582    static constexpr year_month_weekday __from_days(days __d) noexcept;
2583    constexpr days __to_days() const noexcept;
2584};
2585
2586inline constexpr
2587year_month_weekday year_month_weekday::__from_days(days __d) noexcept
2588{
2589    const sys_days      __sysd{__d};
2590    const chrono::weekday __wd = chrono::weekday(__sysd);
2591    const year_month_day __ymd = year_month_day(__sysd);
2592    return year_month_weekday{__ymd.year(), __ymd.month(),
2593                              __wd[(static_cast<unsigned>(__ymd.day())-1)/7+1]};
2594}
2595
2596inline constexpr
2597days year_month_weekday::__to_days() const noexcept
2598{
2599    const sys_days __sysd = sys_days(__y/__m/1);
2600    return (__sysd + (__wdi.weekday() - chrono::weekday(__sysd) + days{(__wdi.index()-1)*7}))
2601                .time_since_epoch();
2602}
2603
2604inline constexpr
2605bool operator==(const year_month_weekday& __lhs, const year_month_weekday& __rhs) noexcept
2606{ return __lhs.year() == __rhs.year() && __lhs.month() == __rhs.month() && __lhs.weekday_indexed() == __rhs.weekday_indexed(); }
2607
2608inline constexpr
2609bool operator!=(const year_month_weekday& __lhs, const year_month_weekday& __rhs) noexcept
2610{ return !(__lhs == __rhs); }
2611
2612inline constexpr
2613year_month_weekday operator/(const year_month& __lhs, const weekday_indexed& __rhs) noexcept
2614{ return year_month_weekday{__lhs.year(), __lhs.month(), __rhs}; }
2615
2616inline constexpr
2617year_month_weekday operator/(const year& __lhs, const month_weekday& __rhs) noexcept
2618{ return year_month_weekday{__lhs, __rhs.month(), __rhs.weekday_indexed()}; }
2619
2620inline constexpr
2621year_month_weekday operator/(int __lhs, const month_weekday& __rhs) noexcept
2622{ return year(__lhs) / __rhs; }
2623
2624inline constexpr
2625year_month_weekday operator/(const month_weekday& __lhs, const year& __rhs) noexcept
2626{ return __rhs / __lhs; }
2627
2628inline constexpr
2629year_month_weekday operator/(const month_weekday& __lhs, int __rhs) noexcept
2630{ return year(__rhs) / __lhs; }
2631
2632
2633inline constexpr
2634year_month_weekday operator+(const year_month_weekday& __lhs, const months& __rhs) noexcept
2635{ return (__lhs.year() / __lhs.month() + __rhs) / __lhs.weekday_indexed(); }
2636
2637inline constexpr
2638year_month_weekday operator+(const months& __lhs, const year_month_weekday& __rhs) noexcept
2639{ return __rhs + __lhs; }
2640
2641inline constexpr
2642year_month_weekday operator-(const year_month_weekday& __lhs, const months& __rhs) noexcept
2643{ return __lhs + (-__rhs); }
2644
2645inline constexpr
2646year_month_weekday operator+(const year_month_weekday& __lhs, const years& __rhs) noexcept
2647{ return year_month_weekday{__lhs.year() + __rhs, __lhs.month(), __lhs.weekday_indexed()}; }
2648
2649inline constexpr
2650year_month_weekday operator+(const years& __lhs, const year_month_weekday& __rhs) noexcept
2651{ return __rhs + __lhs; }
2652
2653inline constexpr
2654year_month_weekday operator-(const year_month_weekday& __lhs, const years& __rhs) noexcept
2655{ return __lhs + (-__rhs); }
2656
2657
2658inline constexpr year_month_weekday& year_month_weekday::operator+=(const months& __dm) noexcept { *this = *this + __dm; return *this; }
2659inline constexpr year_month_weekday& year_month_weekday::operator-=(const months& __dm) noexcept { *this = *this - __dm; return *this; }
2660inline constexpr year_month_weekday& year_month_weekday::operator+=(const years& __dy)  noexcept { *this = *this + __dy; return *this; }
2661inline constexpr year_month_weekday& year_month_weekday::operator-=(const years& __dy)  noexcept { *this = *this - __dy; return *this; }
2662
2663class year_month_weekday_last {
2664private:
2665    chrono::year         __y;
2666    chrono::month        __m;
2667    chrono::weekday_last __wdl;
2668public:
2669    constexpr year_month_weekday_last(const chrono::year& __yval, const chrono::month& __mval,
2670                                      const chrono::weekday_last& __wdlval) noexcept
2671                : __y{__yval}, __m{__mval}, __wdl{__wdlval} {}
2672    constexpr year_month_weekday_last& operator+=(const months& __dm) noexcept;
2673    constexpr year_month_weekday_last& operator-=(const months& __dm) noexcept;
2674    constexpr year_month_weekday_last& operator+=(const years& __dy)  noexcept;
2675    constexpr year_month_weekday_last& operator-=(const years& __dy)  noexcept;
2676
2677    inline constexpr chrono::year                 year() const noexcept { return __y; }
2678    inline constexpr chrono::month               month() const noexcept { return __m; }
2679    inline constexpr chrono::weekday           weekday() const noexcept { return __wdl.weekday(); }
2680    inline constexpr chrono::weekday_last weekday_last() const noexcept { return __wdl; }
2681    inline constexpr operator                 sys_days() const noexcept { return   sys_days{__to_days()}; }
2682    inline explicit constexpr operator      local_days() const noexcept { return local_days{__to_days()}; }
2683    inline constexpr bool ok() const noexcept { return __y.ok() && __m.ok() && __wdl.ok(); }
2684
2685    constexpr days __to_days() const noexcept;
2686
2687};
2688
2689inline constexpr
2690days year_month_weekday_last::__to_days() const noexcept
2691{
2692    const sys_days __last = sys_days{__y/__m/last};
2693    return (__last - (chrono::weekday{__last} - __wdl.weekday())).time_since_epoch();
2694
2695}
2696
2697inline constexpr
2698bool operator==(const year_month_weekday_last& __lhs, const year_month_weekday_last& __rhs) noexcept
2699{ return __lhs.year() == __rhs.year() && __lhs.month() == __rhs.month() && __lhs.weekday_last() == __rhs.weekday_last(); }
2700
2701inline constexpr
2702bool operator!=(const year_month_weekday_last& __lhs, const year_month_weekday_last& __rhs) noexcept
2703{ return !(__lhs == __rhs); }
2704
2705
2706inline constexpr
2707year_month_weekday_last operator/(const year_month& __lhs, const weekday_last& __rhs) noexcept
2708{ return year_month_weekday_last{__lhs.year(), __lhs.month(), __rhs}; }
2709
2710inline constexpr
2711year_month_weekday_last operator/(const year& __lhs, const month_weekday_last& __rhs) noexcept
2712{ return year_month_weekday_last{__lhs, __rhs.month(), __rhs.weekday_last()}; }
2713
2714inline constexpr
2715year_month_weekday_last operator/(int __lhs, const month_weekday_last& __rhs) noexcept
2716{ return year(__lhs) / __rhs; }
2717
2718inline constexpr
2719year_month_weekday_last operator/(const month_weekday_last& __lhs, const year& __rhs) noexcept
2720{ return __rhs / __lhs; }
2721
2722inline constexpr
2723year_month_weekday_last operator/(const month_weekday_last& __lhs, int __rhs) noexcept
2724{ return year(__rhs) / __lhs; }
2725
2726
2727inline constexpr
2728year_month_weekday_last operator+(const year_month_weekday_last& __lhs, const months& __rhs) noexcept
2729{ return (__lhs.year() / __lhs.month() + __rhs) / __lhs.weekday_last(); }
2730
2731inline constexpr
2732year_month_weekday_last operator+(const months& __lhs, const year_month_weekday_last& __rhs) noexcept
2733{ return __rhs + __lhs; }
2734
2735inline constexpr
2736year_month_weekday_last operator-(const year_month_weekday_last& __lhs, const months& __rhs) noexcept
2737{ return __lhs + (-__rhs); }
2738
2739inline constexpr
2740year_month_weekday_last operator+(const year_month_weekday_last& __lhs, const years& __rhs) noexcept
2741{ return year_month_weekday_last{__lhs.year() + __rhs, __lhs.month(), __lhs.weekday_last()}; }
2742
2743inline constexpr
2744year_month_weekday_last operator+(const years& __lhs, const year_month_weekday_last& __rhs) noexcept
2745{ return __rhs + __lhs; }
2746
2747inline constexpr
2748year_month_weekday_last operator-(const year_month_weekday_last& __lhs, const years& __rhs) noexcept
2749{ return __lhs + (-__rhs); }
2750
2751inline constexpr year_month_weekday_last& year_month_weekday_last::operator+=(const months& __dm) noexcept { *this = *this + __dm; return *this; }
2752inline constexpr year_month_weekday_last& year_month_weekday_last::operator-=(const months& __dm) noexcept { *this = *this - __dm; return *this; }
2753inline constexpr year_month_weekday_last& year_month_weekday_last::operator+=(const years& __dy)  noexcept { *this = *this + __dy; return *this; }
2754inline constexpr year_month_weekday_last& year_month_weekday_last::operator-=(const years& __dy)  noexcept { *this = *this - __dy; return *this; }
2755
2756
2757template <class _Duration>
2758class hh_mm_ss
2759{
2760private:
2761    static_assert(__is_duration<_Duration>::value, "template parameter of hh_mm_ss must be a std::chrono::duration");
2762    using __CommonType = common_type_t<_Duration, chrono::seconds>;
2763
2764    static constexpr uint64_t __pow10(unsigned __exp)
2765    {
2766        uint64_t __ret = 1;
2767        for (unsigned __i = 0; __i < __exp; ++__i)
2768            __ret *= 10U;
2769        return __ret;
2770    }
2771
2772    static constexpr unsigned __width(uint64_t __n, uint64_t __d = 10, unsigned __w = 0)
2773    {
2774        if (__n >= 2 && __d != 0 && __w < 19)
2775            return 1 + __width(__n, __d % __n * 10, __w+1);
2776        return 0;
2777    }
2778
2779public:
2780    static unsigned constexpr fractional_width = __width(__CommonType::period::den) < 19 ?
2781                                                 __width(__CommonType::period::den) : 6u;
2782    using precision = duration<typename __CommonType::rep, ratio<1, __pow10(fractional_width)>>;
2783
2784    constexpr hh_mm_ss() noexcept : hh_mm_ss{_Duration::zero()} {}
2785
2786    constexpr explicit hh_mm_ss(_Duration __d) noexcept :
2787        __is_neg(__d < _Duration(0)),
2788        __h(duration_cast<chrono::hours>  (abs(__d))),
2789        __m(duration_cast<chrono::minutes>(abs(__d) - hours())),
2790        __s(duration_cast<chrono::seconds>(abs(__d) - hours() - minutes())),
2791        __f(duration_cast<precision>      (abs(__d) - hours() - minutes() - seconds()))
2792        {}
2793
2794    constexpr bool is_negative()        const noexcept { return __is_neg; }
2795    constexpr chrono::hours hours()     const noexcept { return __h; }
2796    constexpr chrono::minutes minutes() const noexcept { return __m; }
2797    constexpr chrono::seconds seconds() const noexcept { return __s; }
2798    constexpr precision subseconds()    const noexcept { return __f; }
2799
2800    constexpr precision to_duration() const noexcept
2801    {
2802        auto __dur = __h + __m + __s + __f;
2803        return __is_neg ? -__dur : __dur;
2804    }
2805
2806    constexpr explicit operator precision() const noexcept { return to_duration(); }
2807
2808private:
2809    bool            __is_neg;
2810    chrono::hours   __h;
2811    chrono::minutes __m;
2812    chrono::seconds __s;
2813    precision       __f;
2814};
2815
2816constexpr bool is_am(const hours& __h) noexcept { return __h >= hours( 0) && __h < hours(12); }
2817constexpr bool is_pm(const hours& __h) noexcept { return __h >= hours(12) && __h < hours(24); }
2818
2819constexpr hours make12(const hours& __h) noexcept
2820{
2821    if      (__h == hours( 0)) return hours(12);
2822    else if (__h <= hours(12)) return __h;
2823    else                       return __h - hours(12);
2824}
2825
2826constexpr hours make24(const hours& __h, bool __is_pm) noexcept
2827{
2828    if (__is_pm)
2829        return __h == hours(12) ? __h : __h + hours(12);
2830    else
2831        return __h == hours(12) ? hours(0) : __h;
2832}
2833
2834#endif // _LIBCPP_STD_VER > 17
2835} // chrono
2836
2837#if _LIBCPP_STD_VER > 11
2838// Suffixes for duration literals [time.duration.literals]
2839inline namespace literals
2840{
2841  inline namespace chrono_literals
2842  {
2843
2844    constexpr chrono::hours operator""h(unsigned long long __h)
2845    {
2846        return chrono::hours(static_cast<chrono::hours::rep>(__h));
2847    }
2848
2849    constexpr chrono::duration<long double, ratio<3600,1>> operator""h(long double __h)
2850    {
2851        return chrono::duration<long double, ratio<3600,1>>(__h);
2852    }
2853
2854
2855    constexpr chrono::minutes operator""min(unsigned long long __m)
2856    {
2857        return chrono::minutes(static_cast<chrono::minutes::rep>(__m));
2858    }
2859
2860    constexpr chrono::duration<long double, ratio<60,1>> operator""min(long double __m)
2861    {
2862        return chrono::duration<long double, ratio<60,1>> (__m);
2863    }
2864
2865
2866    constexpr chrono::seconds operator""s(unsigned long long __s)
2867    {
2868        return chrono::seconds(static_cast<chrono::seconds::rep>(__s));
2869    }
2870
2871    constexpr chrono::duration<long double> operator""s(long double __s)
2872    {
2873        return chrono::duration<long double> (__s);
2874    }
2875
2876
2877    constexpr chrono::milliseconds operator""ms(unsigned long long __ms)
2878    {
2879        return chrono::milliseconds(static_cast<chrono::milliseconds::rep>(__ms));
2880    }
2881
2882    constexpr chrono::duration<long double, milli> operator""ms(long double __ms)
2883    {
2884        return chrono::duration<long double, milli>(__ms);
2885    }
2886
2887
2888    constexpr chrono::microseconds operator""us(unsigned long long __us)
2889    {
2890        return chrono::microseconds(static_cast<chrono::microseconds::rep>(__us));
2891    }
2892
2893    constexpr chrono::duration<long double, micro> operator""us(long double __us)
2894    {
2895        return chrono::duration<long double, micro> (__us);
2896    }
2897
2898
2899    constexpr chrono::nanoseconds operator""ns(unsigned long long __ns)
2900    {
2901        return chrono::nanoseconds(static_cast<chrono::nanoseconds::rep>(__ns));
2902    }
2903
2904    constexpr chrono::duration<long double, nano> operator""ns(long double __ns)
2905    {
2906        return chrono::duration<long double, nano> (__ns);
2907    }
2908
2909#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CXX20_CHRONO_LITERALS)
2910    constexpr chrono::day operator ""d(unsigned long long __d) noexcept
2911    {
2912        return chrono::day(static_cast<unsigned>(__d));
2913    }
2914
2915    constexpr chrono::year operator ""y(unsigned long long __y) noexcept
2916    {
2917        return chrono::year(static_cast<int>(__y));
2918    }
2919#endif
2920}}
2921
2922namespace chrono { // hoist the literals into namespace std::chrono
2923   using namespace literals::chrono_literals;
2924}
2925
2926#endif
2927
2928_LIBCPP_END_NAMESPACE_STD
2929
2930#ifndef _LIBCPP_CXX03_LANG
2931_LIBCPP_BEGIN_NAMESPACE_FILESYSTEM
2932struct _FilesystemClock {
2933#if !defined(_LIBCPP_HAS_NO_INT128)
2934  typedef __int128_t rep;
2935  typedef nano period;
2936#else
2937  typedef long long rep;
2938  typedef nano period;
2939#endif
2940
2941  typedef chrono::duration<rep, period> duration;
2942  typedef chrono::time_point<_FilesystemClock> time_point;
2943
2944  _LIBCPP_EXPORTED_FROM_ABI
2945  static _LIBCPP_CONSTEXPR_AFTER_CXX11 const bool is_steady = false;
2946
2947  _LIBCPP_AVAILABILITY_FILESYSTEM _LIBCPP_FUNC_VIS static time_point now() noexcept;
2948
2949  _LIBCPP_INLINE_VISIBILITY
2950  static time_t to_time_t(const time_point& __t) noexcept {
2951      typedef chrono::duration<rep> __secs;
2952      return time_t(
2953          chrono::duration_cast<__secs>(__t.time_since_epoch()).count());
2954  }
2955
2956  _LIBCPP_INLINE_VISIBILITY
2957  static time_point from_time_t(time_t __t) noexcept {
2958      typedef chrono::duration<rep> __secs;
2959      return time_point(__secs(__t));
2960  }
2961};
2962_LIBCPP_END_NAMESPACE_FILESYSTEM
2963#endif // !_LIBCPP_CXX03_LANG
2964
2965_LIBCPP_POP_MACROS
2966
2967#endif  // _LIBCPP_CHRONO
2968