xref: /freebsd/contrib/llvm-project/libcxx/include/chrono (revision 580744621f33383027108364dcadad718df46ffe)
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 <ctime>
828#include <type_traits>
829#include <ratio>
830#include <limits>
831#include <version>
832
833#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
834#pragma GCC system_header
835#endif
836
837_LIBCPP_PUSH_MACROS
838#include <__undef_macros>
839
840#ifndef _LIBCPP_CXX03_LANG
841_LIBCPP_BEGIN_NAMESPACE_FILESYSTEM
842struct _FilesystemClock;
843_LIBCPP_END_NAMESPACE_FILESYSTEM
844#endif // !_LIBCPP_CXX03_LANG
845
846_LIBCPP_BEGIN_NAMESPACE_STD
847
848namespace chrono
849{
850
851template <class _Rep, class _Period = ratio<1> > class _LIBCPP_TEMPLATE_VIS duration;
852
853template <class _Tp>
854struct __is_duration : false_type {};
855
856template <class _Rep, class _Period>
857struct __is_duration<duration<_Rep, _Period> > : true_type  {};
858
859template <class _Rep, class _Period>
860struct __is_duration<const duration<_Rep, _Period> > : true_type  {};
861
862template <class _Rep, class _Period>
863struct __is_duration<volatile duration<_Rep, _Period> > : true_type  {};
864
865template <class _Rep, class _Period>
866struct __is_duration<const volatile duration<_Rep, _Period> > : true_type  {};
867
868} // chrono
869
870template <class _Rep1, class _Period1, class _Rep2, class _Period2>
871struct _LIBCPP_TEMPLATE_VIS common_type<chrono::duration<_Rep1, _Period1>,
872                                         chrono::duration<_Rep2, _Period2> >
873{
874    typedef chrono::duration<typename common_type<_Rep1, _Rep2>::type,
875                             typename __ratio_gcd<_Period1, _Period2>::type> type;
876};
877
878namespace chrono {
879
880// duration_cast
881
882template <class _FromDuration, class _ToDuration,
883          class _Period = typename ratio_divide<typename _FromDuration::period, typename _ToDuration::period>::type,
884          bool = _Period::num == 1,
885          bool = _Period::den == 1>
886struct __duration_cast;
887
888template <class _FromDuration, class _ToDuration, class _Period>
889struct __duration_cast<_FromDuration, _ToDuration, _Period, true, true>
890{
891    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
892    _ToDuration operator()(const _FromDuration& __fd) const
893    {
894        return _ToDuration(static_cast<typename _ToDuration::rep>(__fd.count()));
895    }
896};
897
898template <class _FromDuration, class _ToDuration, class _Period>
899struct __duration_cast<_FromDuration, _ToDuration, _Period, true, false>
900{
901    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
902    _ToDuration operator()(const _FromDuration& __fd) const
903    {
904        typedef typename common_type<typename _ToDuration::rep, typename _FromDuration::rep, intmax_t>::type _Ct;
905        return _ToDuration(static_cast<typename _ToDuration::rep>(
906                           static_cast<_Ct>(__fd.count()) / static_cast<_Ct>(_Period::den)));
907    }
908};
909
910template <class _FromDuration, class _ToDuration, class _Period>
911struct __duration_cast<_FromDuration, _ToDuration, _Period, false, true>
912{
913    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
914    _ToDuration operator()(const _FromDuration& __fd) const
915    {
916        typedef typename common_type<typename _ToDuration::rep, typename _FromDuration::rep, intmax_t>::type _Ct;
917        return _ToDuration(static_cast<typename _ToDuration::rep>(
918                           static_cast<_Ct>(__fd.count()) * static_cast<_Ct>(_Period::num)));
919    }
920};
921
922template <class _FromDuration, class _ToDuration, class _Period>
923struct __duration_cast<_FromDuration, _ToDuration, _Period, false, false>
924{
925    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
926    _ToDuration operator()(const _FromDuration& __fd) const
927    {
928        typedef typename common_type<typename _ToDuration::rep, typename _FromDuration::rep, intmax_t>::type _Ct;
929        return _ToDuration(static_cast<typename _ToDuration::rep>(
930                           static_cast<_Ct>(__fd.count()) * static_cast<_Ct>(_Period::num)
931                                                          / static_cast<_Ct>(_Period::den)));
932    }
933};
934
935template <class _ToDuration, class _Rep, class _Period>
936inline _LIBCPP_INLINE_VISIBILITY
937_LIBCPP_CONSTEXPR
938typename enable_if
939<
940    __is_duration<_ToDuration>::value,
941    _ToDuration
942>::type
943duration_cast(const duration<_Rep, _Period>& __fd)
944{
945    return __duration_cast<duration<_Rep, _Period>, _ToDuration>()(__fd);
946}
947
948template <class _Rep>
949struct _LIBCPP_TEMPLATE_VIS treat_as_floating_point : is_floating_point<_Rep> {};
950
951#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
952template <class _Rep>
953_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool treat_as_floating_point_v
954    = treat_as_floating_point<_Rep>::value;
955#endif
956
957template <class _Rep>
958struct _LIBCPP_TEMPLATE_VIS duration_values
959{
960public:
961    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR _Rep zero() _NOEXCEPT {return _Rep(0);}
962    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR _Rep max()  _NOEXCEPT {return numeric_limits<_Rep>::max();}
963    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR _Rep min()  _NOEXCEPT {return numeric_limits<_Rep>::lowest();}
964};
965
966#if _LIBCPP_STD_VER > 14
967template <class _ToDuration, class _Rep, class _Period>
968inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
969typename enable_if
970<
971    __is_duration<_ToDuration>::value,
972    _ToDuration
973>::type
974floor(const duration<_Rep, _Period>& __d)
975{
976    _ToDuration __t = duration_cast<_ToDuration>(__d);
977    if (__t > __d)
978        __t = __t - _ToDuration{1};
979    return __t;
980}
981
982template <class _ToDuration, class _Rep, class _Period>
983inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
984typename enable_if
985<
986    __is_duration<_ToDuration>::value,
987    _ToDuration
988>::type
989ceil(const duration<_Rep, _Period>& __d)
990{
991    _ToDuration __t = duration_cast<_ToDuration>(__d);
992    if (__t < __d)
993        __t = __t + _ToDuration{1};
994    return __t;
995}
996
997template <class _ToDuration, class _Rep, class _Period>
998inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
999typename enable_if
1000<
1001    __is_duration<_ToDuration>::value,
1002    _ToDuration
1003>::type
1004round(const duration<_Rep, _Period>& __d)
1005{
1006    _ToDuration __lower = floor<_ToDuration>(__d);
1007    _ToDuration __upper = __lower + _ToDuration{1};
1008    auto __lowerDiff = __d - __lower;
1009    auto __upperDiff = __upper - __d;
1010    if (__lowerDiff < __upperDiff)
1011        return __lower;
1012    if (__lowerDiff > __upperDiff)
1013        return __upper;
1014    return __lower.count() & 1 ? __upper : __lower;
1015}
1016#endif
1017
1018// duration
1019
1020template <class _Rep, class _Period>
1021class _LIBCPP_TEMPLATE_VIS duration
1022{
1023    static_assert(!__is_duration<_Rep>::value, "A duration representation can not be a duration");
1024    static_assert(__is_ratio<_Period>::value, "Second template parameter of duration must be a std::ratio");
1025    static_assert(_Period::num > 0, "duration period must be positive");
1026
1027    template <class _R1, class _R2>
1028    struct __no_overflow
1029    {
1030    private:
1031        static const intmax_t __gcd_n1_n2 = __static_gcd<_R1::num, _R2::num>::value;
1032        static const intmax_t __gcd_d1_d2 = __static_gcd<_R1::den, _R2::den>::value;
1033        static const intmax_t __n1 = _R1::num / __gcd_n1_n2;
1034        static const intmax_t __d1 = _R1::den / __gcd_d1_d2;
1035        static const intmax_t __n2 = _R2::num / __gcd_n1_n2;
1036        static const intmax_t __d2 = _R2::den / __gcd_d1_d2;
1037        static const intmax_t max = -((intmax_t(1) << (sizeof(intmax_t) * CHAR_BIT - 1)) + 1);
1038
1039        template <intmax_t _Xp, intmax_t _Yp, bool __overflow>
1040        struct __mul    // __overflow == false
1041        {
1042            static const intmax_t value = _Xp * _Yp;
1043        };
1044
1045        template <intmax_t _Xp, intmax_t _Yp>
1046        struct __mul<_Xp, _Yp, true>
1047        {
1048            static const intmax_t value = 1;
1049        };
1050
1051    public:
1052        static const bool value = (__n1 <= max / __d2) && (__n2 <= max / __d1);
1053        typedef ratio<__mul<__n1, __d2, !value>::value,
1054                      __mul<__n2, __d1, !value>::value> type;
1055    };
1056
1057public:
1058    typedef _Rep rep;
1059    typedef typename _Period::type period;
1060private:
1061    rep __rep_;
1062public:
1063
1064    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1065#ifndef _LIBCPP_CXX03_LANG
1066        duration() = default;
1067#else
1068        duration() {}
1069#endif
1070
1071    template <class _Rep2>
1072        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1073        explicit duration(const _Rep2& __r,
1074            typename enable_if
1075            <
1076               is_convertible<_Rep2, rep>::value &&
1077               (treat_as_floating_point<rep>::value ||
1078               !treat_as_floating_point<_Rep2>::value)
1079            >::type* = 0)
1080                : __rep_(__r) {}
1081
1082    // conversions
1083    template <class _Rep2, class _Period2>
1084        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1085        duration(const duration<_Rep2, _Period2>& __d,
1086            typename enable_if
1087            <
1088                __no_overflow<_Period2, period>::value && (
1089                treat_as_floating_point<rep>::value ||
1090                (__no_overflow<_Period2, period>::type::den == 1 &&
1091                 !treat_as_floating_point<_Rep2>::value))
1092            >::type* = 0)
1093                : __rep_(_VSTD::chrono::duration_cast<duration>(__d).count()) {}
1094
1095    // observer
1096
1097    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR rep count() const {return __rep_;}
1098
1099    // arithmetic
1100
1101    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR typename common_type<duration>::type operator+() const {return typename common_type<duration>::type(*this);}
1102    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR typename common_type<duration>::type operator-() const {return typename common_type<duration>::type(-__rep_);}
1103    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration& operator++()      {++__rep_; return *this;}
1104    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration  operator++(int)   {return duration(__rep_++);}
1105    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration& operator--()      {--__rep_; return *this;}
1106    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration  operator--(int)   {return duration(__rep_--);}
1107
1108    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration& operator+=(const duration& __d) {__rep_ += __d.count(); return *this;}
1109    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration& operator-=(const duration& __d) {__rep_ -= __d.count(); return *this;}
1110
1111    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration& operator*=(const rep& rhs) {__rep_ *= rhs; return *this;}
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 duration& rhs) {__rep_ %= rhs.count(); return *this;}
1115
1116    // special values
1117
1118    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR duration zero() _NOEXCEPT {return duration(duration_values<rep>::zero());}
1119    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR duration min()  _NOEXCEPT {return duration(duration_values<rep>::min());}
1120    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR duration max()  _NOEXCEPT {return duration(duration_values<rep>::max());}
1121};
1122
1123typedef duration<long long,         nano> nanoseconds;
1124typedef duration<long long,        micro> microseconds;
1125typedef duration<long long,        milli> milliseconds;
1126typedef duration<long long              > seconds;
1127typedef duration<     long, ratio<  60> > minutes;
1128typedef duration<     long, ratio<3600> > hours;
1129#if _LIBCPP_STD_VER > 17
1130typedef duration<     int, ratio_multiply<ratio<24>, hours::period>>         days;
1131typedef duration<     int, ratio_multiply<ratio<7>,   days::period>>         weeks;
1132typedef duration<     int, ratio_multiply<ratio<146097, 400>, days::period>> years;
1133typedef duration<     int, ratio_divide<years::period, ratio<12>>>           months;
1134#endif
1135// Duration ==
1136
1137template <class _LhsDuration, class _RhsDuration>
1138struct __duration_eq
1139{
1140    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1141    bool operator()(const _LhsDuration& __lhs, const _RhsDuration& __rhs) const
1142        {
1143            typedef typename common_type<_LhsDuration, _RhsDuration>::type _Ct;
1144            return _Ct(__lhs).count() == _Ct(__rhs).count();
1145        }
1146};
1147
1148template <class _LhsDuration>
1149struct __duration_eq<_LhsDuration, _LhsDuration>
1150{
1151    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1152    bool operator()(const _LhsDuration& __lhs, const _LhsDuration& __rhs) const
1153        {return __lhs.count() == __rhs.count();}
1154};
1155
1156template <class _Rep1, class _Period1, class _Rep2, class _Period2>
1157inline _LIBCPP_INLINE_VISIBILITY
1158_LIBCPP_CONSTEXPR
1159bool
1160operator==(const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
1161{
1162    return __duration_eq<duration<_Rep1, _Period1>, duration<_Rep2, _Period2> >()(__lhs, __rhs);
1163}
1164
1165// Duration !=
1166
1167template <class _Rep1, class _Period1, class _Rep2, class _Period2>
1168inline _LIBCPP_INLINE_VISIBILITY
1169_LIBCPP_CONSTEXPR
1170bool
1171operator!=(const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
1172{
1173    return !(__lhs == __rhs);
1174}
1175
1176// Duration <
1177
1178template <class _LhsDuration, class _RhsDuration>
1179struct __duration_lt
1180{
1181    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1182    bool operator()(const _LhsDuration& __lhs, const _RhsDuration& __rhs) const
1183        {
1184            typedef typename common_type<_LhsDuration, _RhsDuration>::type _Ct;
1185            return _Ct(__lhs).count() < _Ct(__rhs).count();
1186        }
1187};
1188
1189template <class _LhsDuration>
1190struct __duration_lt<_LhsDuration, _LhsDuration>
1191{
1192    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1193    bool operator()(const _LhsDuration& __lhs, const _LhsDuration& __rhs) const
1194        {return __lhs.count() < __rhs.count();}
1195};
1196
1197template <class _Rep1, class _Period1, class _Rep2, class _Period2>
1198inline _LIBCPP_INLINE_VISIBILITY
1199_LIBCPP_CONSTEXPR
1200bool
1201operator< (const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
1202{
1203    return __duration_lt<duration<_Rep1, _Period1>, duration<_Rep2, _Period2> >()(__lhs, __rhs);
1204}
1205
1206// Duration >
1207
1208template <class _Rep1, class _Period1, class _Rep2, class _Period2>
1209inline _LIBCPP_INLINE_VISIBILITY
1210_LIBCPP_CONSTEXPR
1211bool
1212operator> (const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
1213{
1214    return __rhs < __lhs;
1215}
1216
1217// Duration <=
1218
1219template <class _Rep1, class _Period1, class _Rep2, class _Period2>
1220inline _LIBCPP_INLINE_VISIBILITY
1221_LIBCPP_CONSTEXPR
1222bool
1223operator<=(const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
1224{
1225    return !(__rhs < __lhs);
1226}
1227
1228// Duration >=
1229
1230template <class _Rep1, class _Period1, class _Rep2, class _Period2>
1231inline _LIBCPP_INLINE_VISIBILITY
1232_LIBCPP_CONSTEXPR
1233bool
1234operator>=(const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
1235{
1236    return !(__lhs < __rhs);
1237}
1238
1239// Duration +
1240
1241template <class _Rep1, class _Period1, class _Rep2, class _Period2>
1242inline _LIBCPP_INLINE_VISIBILITY
1243_LIBCPP_CONSTEXPR
1244typename common_type<duration<_Rep1, _Period1>, duration<_Rep2, _Period2> >::type
1245operator+(const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
1246{
1247    typedef typename common_type<duration<_Rep1, _Period1>, duration<_Rep2, _Period2> >::type _Cd;
1248    return _Cd(_Cd(__lhs).count() + _Cd(__rhs).count());
1249}
1250
1251// Duration -
1252
1253template <class _Rep1, class _Period1, class _Rep2, class _Period2>
1254inline _LIBCPP_INLINE_VISIBILITY
1255_LIBCPP_CONSTEXPR
1256typename common_type<duration<_Rep1, _Period1>, duration<_Rep2, _Period2> >::type
1257operator-(const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
1258{
1259    typedef typename common_type<duration<_Rep1, _Period1>, duration<_Rep2, _Period2> >::type _Cd;
1260    return _Cd(_Cd(__lhs).count() - _Cd(__rhs).count());
1261}
1262
1263// Duration *
1264
1265template <class _Rep1, class _Period, class _Rep2>
1266inline _LIBCPP_INLINE_VISIBILITY
1267_LIBCPP_CONSTEXPR
1268typename enable_if
1269<
1270    is_convertible<_Rep2, typename common_type<_Rep1, _Rep2>::type>::value,
1271    duration<typename common_type<_Rep1, _Rep2>::type, _Period>
1272>::type
1273operator*(const duration<_Rep1, _Period>& __d, const _Rep2& __s)
1274{
1275    typedef typename common_type<_Rep1, _Rep2>::type _Cr;
1276    typedef duration<_Cr, _Period> _Cd;
1277    return _Cd(_Cd(__d).count() * static_cast<_Cr>(__s));
1278}
1279
1280template <class _Rep1, class _Period, class _Rep2>
1281inline _LIBCPP_INLINE_VISIBILITY
1282_LIBCPP_CONSTEXPR
1283typename enable_if
1284<
1285    is_convertible<_Rep1, typename common_type<_Rep1, _Rep2>::type>::value,
1286    duration<typename common_type<_Rep1, _Rep2>::type, _Period>
1287>::type
1288operator*(const _Rep1& __s, const duration<_Rep2, _Period>& __d)
1289{
1290    return __d * __s;
1291}
1292
1293// Duration /
1294
1295template <class _Rep1, class _Period, class _Rep2>
1296inline _LIBCPP_INLINE_VISIBILITY
1297_LIBCPP_CONSTEXPR
1298typename enable_if
1299<
1300    !__is_duration<_Rep2>::value &&
1301      is_convertible<_Rep2, typename common_type<_Rep1, _Rep2>::type>::value,
1302    duration<typename common_type<_Rep1, _Rep2>::type, _Period>
1303>::type
1304operator/(const duration<_Rep1, _Period>& __d, const _Rep2& __s)
1305{
1306    typedef typename common_type<_Rep1, _Rep2>::type _Cr;
1307    typedef duration<_Cr, _Period> _Cd;
1308    return _Cd(_Cd(__d).count() / static_cast<_Cr>(__s));
1309}
1310
1311template <class _Rep1, class _Period1, class _Rep2, class _Period2>
1312inline _LIBCPP_INLINE_VISIBILITY
1313_LIBCPP_CONSTEXPR
1314typename common_type<_Rep1, _Rep2>::type
1315operator/(const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
1316{
1317    typedef typename common_type<duration<_Rep1, _Period1>, duration<_Rep2, _Period2> >::type _Ct;
1318    return _Ct(__lhs).count() / _Ct(__rhs).count();
1319}
1320
1321// Duration %
1322
1323template <class _Rep1, class _Period, class _Rep2>
1324inline _LIBCPP_INLINE_VISIBILITY
1325_LIBCPP_CONSTEXPR
1326typename enable_if
1327<
1328    !__is_duration<_Rep2>::value &&
1329      is_convertible<_Rep2, typename common_type<_Rep1, _Rep2>::type>::value,
1330    duration<typename common_type<_Rep1, _Rep2>::type, _Period>
1331>::type
1332operator%(const duration<_Rep1, _Period>& __d, const _Rep2& __s)
1333{
1334    typedef typename common_type<_Rep1, _Rep2>::type _Cr;
1335    typedef duration<_Cr, _Period> _Cd;
1336    return _Cd(_Cd(__d).count() % static_cast<_Cr>(__s));
1337}
1338
1339template <class _Rep1, class _Period1, class _Rep2, class _Period2>
1340inline _LIBCPP_INLINE_VISIBILITY
1341_LIBCPP_CONSTEXPR
1342typename common_type<duration<_Rep1, _Period1>, duration<_Rep2, _Period2> >::type
1343operator%(const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
1344{
1345    typedef typename common_type<_Rep1, _Rep2>::type _Cr;
1346    typedef typename common_type<duration<_Rep1, _Period1>, duration<_Rep2, _Period2> >::type _Cd;
1347    return _Cd(static_cast<_Cr>(_Cd(__lhs).count()) % static_cast<_Cr>(_Cd(__rhs).count()));
1348}
1349
1350//////////////////////////////////////////////////////////
1351///////////////////// time_point /////////////////////////
1352//////////////////////////////////////////////////////////
1353
1354template <class _Clock, class _Duration = typename _Clock::duration>
1355class _LIBCPP_TEMPLATE_VIS time_point
1356{
1357    static_assert(__is_duration<_Duration>::value,
1358                  "Second template parameter of time_point must be a std::chrono::duration");
1359public:
1360    typedef _Clock                    clock;
1361    typedef _Duration                 duration;
1362    typedef typename duration::rep    rep;
1363    typedef typename duration::period period;
1364private:
1365    duration __d_;
1366
1367public:
1368    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 time_point() : __d_(duration::zero()) {}
1369    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 explicit time_point(const duration& __d) : __d_(__d) {}
1370
1371    // conversions
1372    template <class _Duration2>
1373    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1374    time_point(const time_point<clock, _Duration2>& t,
1375        typename enable_if
1376        <
1377            is_convertible<_Duration2, duration>::value
1378        >::type* = 0)
1379            : __d_(t.time_since_epoch()) {}
1380
1381    // observer
1382
1383    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 duration time_since_epoch() const {return __d_;}
1384
1385    // arithmetic
1386
1387    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 time_point& operator+=(const duration& __d) {__d_ += __d; return *this;}
1388    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 time_point& operator-=(const duration& __d) {__d_ -= __d; return *this;}
1389
1390    // special values
1391
1392    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR time_point min() _NOEXCEPT {return time_point(duration::min());}
1393    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR time_point max() _NOEXCEPT {return time_point(duration::max());}
1394};
1395
1396} // chrono
1397
1398template <class _Clock, class _Duration1, class _Duration2>
1399struct _LIBCPP_TEMPLATE_VIS common_type<chrono::time_point<_Clock, _Duration1>,
1400                                         chrono::time_point<_Clock, _Duration2> >
1401{
1402    typedef chrono::time_point<_Clock, typename common_type<_Duration1, _Duration2>::type> type;
1403};
1404
1405namespace chrono {
1406
1407template <class _ToDuration, class _Clock, class _Duration>
1408inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1409time_point<_Clock, _ToDuration>
1410time_point_cast(const time_point<_Clock, _Duration>& __t)
1411{
1412    return time_point<_Clock, _ToDuration>(_VSTD::chrono::duration_cast<_ToDuration>(__t.time_since_epoch()));
1413}
1414
1415#if _LIBCPP_STD_VER > 14
1416template <class _ToDuration, class _Clock, class _Duration>
1417inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1418typename enable_if
1419<
1420    __is_duration<_ToDuration>::value,
1421    time_point<_Clock, _ToDuration>
1422>::type
1423floor(const time_point<_Clock, _Duration>& __t)
1424{
1425    return time_point<_Clock, _ToDuration>{floor<_ToDuration>(__t.time_since_epoch())};
1426}
1427
1428template <class _ToDuration, class _Clock, class _Duration>
1429inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1430typename enable_if
1431<
1432    __is_duration<_ToDuration>::value,
1433    time_point<_Clock, _ToDuration>
1434>::type
1435ceil(const time_point<_Clock, _Duration>& __t)
1436{
1437    return time_point<_Clock, _ToDuration>{ceil<_ToDuration>(__t.time_since_epoch())};
1438}
1439
1440template <class _ToDuration, class _Clock, class _Duration>
1441inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1442typename enable_if
1443<
1444    __is_duration<_ToDuration>::value,
1445    time_point<_Clock, _ToDuration>
1446>::type
1447round(const time_point<_Clock, _Duration>& __t)
1448{
1449    return time_point<_Clock, _ToDuration>{round<_ToDuration>(__t.time_since_epoch())};
1450}
1451
1452template <class _Rep, class _Period>
1453inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1454typename enable_if
1455<
1456    numeric_limits<_Rep>::is_signed,
1457    duration<_Rep, _Period>
1458>::type
1459abs(duration<_Rep, _Period> __d)
1460{
1461    return __d >= __d.zero() ? +__d : -__d;
1462}
1463#endif
1464
1465// time_point ==
1466
1467template <class _Clock, class _Duration1, class _Duration2>
1468inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1469bool
1470operator==(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
1471{
1472    return __lhs.time_since_epoch() == __rhs.time_since_epoch();
1473}
1474
1475// time_point !=
1476
1477template <class _Clock, class _Duration1, class _Duration2>
1478inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1479bool
1480operator!=(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
1481{
1482    return !(__lhs == __rhs);
1483}
1484
1485// time_point <
1486
1487template <class _Clock, class _Duration1, class _Duration2>
1488inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1489bool
1490operator<(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
1491{
1492    return __lhs.time_since_epoch() < __rhs.time_since_epoch();
1493}
1494
1495// time_point >
1496
1497template <class _Clock, class _Duration1, class _Duration2>
1498inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1499bool
1500operator>(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
1501{
1502    return __rhs < __lhs;
1503}
1504
1505// time_point <=
1506
1507template <class _Clock, class _Duration1, class _Duration2>
1508inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1509bool
1510operator<=(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
1511{
1512    return !(__rhs < __lhs);
1513}
1514
1515// time_point >=
1516
1517template <class _Clock, class _Duration1, class _Duration2>
1518inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1519bool
1520operator>=(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
1521{
1522    return !(__lhs < __rhs);
1523}
1524
1525// time_point operator+(time_point x, duration y);
1526
1527template <class _Clock, class _Duration1, class _Rep2, class _Period2>
1528inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1529time_point<_Clock, typename common_type<_Duration1, duration<_Rep2, _Period2> >::type>
1530operator+(const time_point<_Clock, _Duration1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
1531{
1532    typedef time_point<_Clock, typename common_type<_Duration1, duration<_Rep2, _Period2> >::type> _Tr;
1533    return _Tr (__lhs.time_since_epoch() + __rhs);
1534}
1535
1536// time_point operator+(duration x, time_point y);
1537
1538template <class _Rep1, class _Period1, class _Clock, class _Duration2>
1539inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1540time_point<_Clock, typename common_type<duration<_Rep1, _Period1>, _Duration2>::type>
1541operator+(const duration<_Rep1, _Period1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
1542{
1543    return __rhs + __lhs;
1544}
1545
1546// time_point operator-(time_point x, duration y);
1547
1548template <class _Clock, class _Duration1, class _Rep2, class _Period2>
1549inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1550time_point<_Clock, typename common_type<_Duration1, duration<_Rep2, _Period2> >::type>
1551operator-(const time_point<_Clock, _Duration1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
1552{
1553    typedef time_point<_Clock, typename common_type<_Duration1, duration<_Rep2, _Period2> >::type> _Ret;
1554    return _Ret(__lhs.time_since_epoch() -__rhs);
1555}
1556
1557// duration operator-(time_point x, time_point y);
1558
1559template <class _Clock, class _Duration1, class _Duration2>
1560inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1561typename common_type<_Duration1, _Duration2>::type
1562operator-(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
1563{
1564    return __lhs.time_since_epoch() - __rhs.time_since_epoch();
1565}
1566
1567//////////////////////////////////////////////////////////
1568/////////////////////// clocks ///////////////////////////
1569//////////////////////////////////////////////////////////
1570
1571class _LIBCPP_TYPE_VIS system_clock
1572{
1573public:
1574    typedef microseconds                     duration;
1575    typedef duration::rep                    rep;
1576    typedef duration::period                 period;
1577    typedef chrono::time_point<system_clock> time_point;
1578    static _LIBCPP_CONSTEXPR_AFTER_CXX11 const bool is_steady = false;
1579
1580    static time_point now() _NOEXCEPT;
1581    static time_t     to_time_t  (const time_point& __t) _NOEXCEPT;
1582    static time_point from_time_t(time_t __t) _NOEXCEPT;
1583};
1584
1585#ifndef _LIBCPP_HAS_NO_MONOTONIC_CLOCK
1586class _LIBCPP_TYPE_VIS steady_clock
1587{
1588public:
1589    typedef nanoseconds                                   duration;
1590    typedef duration::rep                                 rep;
1591    typedef duration::period                              period;
1592    typedef chrono::time_point<steady_clock, duration>    time_point;
1593    static _LIBCPP_CONSTEXPR_AFTER_CXX11 const bool is_steady = true;
1594
1595    static time_point now() _NOEXCEPT;
1596};
1597
1598typedef steady_clock high_resolution_clock;
1599#else
1600typedef system_clock high_resolution_clock;
1601#endif
1602
1603#if _LIBCPP_STD_VER > 17
1604// [time.clock.file], type file_clock
1605using file_clock = _VSTD_FS::_FilesystemClock;
1606
1607template<class _Duration>
1608using file_time = time_point<file_clock, _Duration>;
1609
1610
1611template <class _Duration>
1612using sys_time    = time_point<system_clock, _Duration>;
1613using sys_seconds = sys_time<seconds>;
1614using sys_days    = sys_time<days>;
1615
1616struct local_t {};
1617template<class Duration>
1618using local_time  = time_point<local_t, Duration>;
1619using local_seconds = local_time<seconds>;
1620using local_days    = local_time<days>;
1621
1622
1623struct last_spec { explicit last_spec() = default; };
1624
1625class day {
1626private:
1627    unsigned char __d;
1628public:
1629    day() = default;
1630    explicit inline constexpr day(unsigned __val) noexcept : __d(static_cast<unsigned char>(__val)) {}
1631    inline constexpr day& operator++()    noexcept { ++__d; return *this; }
1632    inline constexpr day  operator++(int) noexcept { day __tmp = *this; ++(*this); return __tmp; }
1633    inline constexpr day& operator--()    noexcept { --__d; return *this; }
1634    inline constexpr day  operator--(int) noexcept { day __tmp = *this; --(*this); return __tmp; }
1635           constexpr day& operator+=(const days& __dd) noexcept;
1636           constexpr day& operator-=(const days& __dd) noexcept;
1637    explicit inline constexpr operator unsigned() const noexcept { return __d; }
1638    inline constexpr bool ok() const noexcept { return __d >= 1 && __d <= 31; }
1639  };
1640
1641
1642inline constexpr
1643bool operator==(const day& __lhs, const day& __rhs) noexcept
1644{ return static_cast<unsigned>(__lhs) == static_cast<unsigned>(__rhs); }
1645
1646inline constexpr
1647bool operator!=(const day& __lhs, const day& __rhs) noexcept
1648{ return !(__lhs == __rhs); }
1649
1650inline constexpr
1651bool operator< (const day& __lhs, const day& __rhs) noexcept
1652{ return static_cast<unsigned>(__lhs) <  static_cast<unsigned>(__rhs); }
1653
1654inline constexpr
1655bool operator> (const day& __lhs, const day& __rhs) noexcept
1656{ return __rhs < __lhs; }
1657
1658inline constexpr
1659bool operator<=(const day& __lhs, const day& __rhs) noexcept
1660{ return !(__rhs < __lhs);}
1661
1662inline constexpr
1663bool operator>=(const day& __lhs, const day& __rhs) noexcept
1664{ return !(__lhs < __rhs); }
1665
1666inline constexpr
1667day operator+ (const day& __lhs, const days& __rhs) noexcept
1668{ return day(static_cast<unsigned>(__lhs) + __rhs.count()); }
1669
1670inline constexpr
1671day operator+ (const days& __lhs, const day& __rhs) noexcept
1672{ return __rhs + __lhs; }
1673
1674inline constexpr
1675day operator- (const day& __lhs, const days& __rhs) noexcept
1676{ return __lhs + -__rhs; }
1677
1678inline constexpr
1679days operator-(const day& __lhs, const day& __rhs) noexcept
1680{ return days(static_cast<int>(static_cast<unsigned>(__lhs)) -
1681              static_cast<int>(static_cast<unsigned>(__rhs))); }
1682
1683inline constexpr day& day::operator+=(const days& __dd) noexcept
1684{ *this = *this + __dd; return *this; }
1685
1686inline constexpr day& day::operator-=(const days& __dd) noexcept
1687{ *this = *this - __dd; return *this; }
1688
1689
1690class month {
1691private:
1692    unsigned char __m;
1693public:
1694    month() = default;
1695    explicit inline constexpr month(unsigned __val) noexcept : __m(static_cast<unsigned char>(__val)) {}
1696    inline constexpr month& operator++()    noexcept { ++__m; return *this; }
1697    inline constexpr month  operator++(int) noexcept { month __tmp = *this; ++(*this); return __tmp; }
1698    inline constexpr month& operator--()    noexcept { --__m; return *this; }
1699    inline constexpr month  operator--(int) noexcept { month __tmp = *this; --(*this); return __tmp; }
1700           constexpr month& operator+=(const months& __m1) noexcept;
1701           constexpr month& operator-=(const months& __m1) noexcept;
1702    explicit inline constexpr operator unsigned() const noexcept { return __m; }
1703    inline constexpr bool ok() const noexcept { return __m >= 1 && __m <= 12; }
1704};
1705
1706
1707inline constexpr
1708bool operator==(const month& __lhs, const month& __rhs) noexcept
1709{ return static_cast<unsigned>(__lhs) == static_cast<unsigned>(__rhs); }
1710
1711inline constexpr
1712bool operator!=(const month& __lhs, const month& __rhs) noexcept
1713{ return !(__lhs == __rhs); }
1714
1715inline constexpr
1716bool operator< (const month& __lhs, const month& __rhs) noexcept
1717{ return static_cast<unsigned>(__lhs)  < static_cast<unsigned>(__rhs); }
1718
1719inline constexpr
1720bool operator> (const month& __lhs, const month& __rhs) noexcept
1721{ return __rhs < __lhs; }
1722
1723inline constexpr
1724bool operator<=(const month& __lhs, const month& __rhs) noexcept
1725{ return !(__rhs < __lhs); }
1726
1727inline constexpr
1728bool operator>=(const month& __lhs, const month& __rhs) noexcept
1729{ return !(__lhs < __rhs); }
1730
1731inline constexpr
1732month operator+ (const month& __lhs, const months& __rhs) noexcept
1733{
1734    auto const __mu = static_cast<long long>(static_cast<unsigned>(__lhs)) + (__rhs.count() - 1);
1735    auto const __yr = (__mu >= 0 ? __mu : __mu - 11) / 12;
1736    return month{static_cast<unsigned>(__mu - __yr * 12 + 1)};
1737}
1738
1739inline constexpr
1740month operator+ (const months& __lhs, const month& __rhs) noexcept
1741{ return __rhs + __lhs; }
1742
1743inline constexpr
1744month operator- (const month& __lhs, const months& __rhs) noexcept
1745{ return __lhs + -__rhs; }
1746
1747inline constexpr
1748months operator-(const month& __lhs, const month& __rhs) noexcept
1749{
1750    auto const __dm = static_cast<unsigned>(__lhs) - static_cast<unsigned>(__rhs);
1751    return months(__dm <= 11 ? __dm : __dm + 12);
1752}
1753
1754inline constexpr month& month::operator+=(const months& __dm) noexcept
1755{ *this = *this + __dm; return *this; }
1756
1757inline constexpr month& month::operator-=(const months& __dm) noexcept
1758{ *this = *this - __dm; return *this; }
1759
1760
1761class year {
1762private:
1763    short __y;
1764public:
1765    year() = default;
1766    explicit inline constexpr year(int __val) noexcept : __y(static_cast<short>(__val)) {}
1767
1768    inline constexpr year& operator++()    noexcept { ++__y; return *this; }
1769    inline constexpr year  operator++(int) noexcept { year __tmp = *this; ++(*this); return __tmp; }
1770    inline constexpr year& operator--()    noexcept { --__y; return *this; }
1771    inline constexpr year  operator--(int) noexcept { year __tmp = *this; --(*this); return __tmp; }
1772           constexpr year& operator+=(const years& __dy) noexcept;
1773           constexpr year& operator-=(const years& __dy) noexcept;
1774    inline constexpr year operator+() const noexcept { return *this; }
1775    inline constexpr year operator-() const noexcept { return year{-__y}; }
1776
1777    inline constexpr bool is_leap() const noexcept { return __y % 4 == 0 && (__y % 100 != 0 || __y % 400 == 0); }
1778    explicit inline constexpr operator int() const noexcept { return __y; }
1779           constexpr bool ok() const noexcept;
1780    static inline constexpr year min() noexcept { return year{-32767}; }
1781    static inline constexpr year max() noexcept { return year{ 32767}; }
1782};
1783
1784
1785inline constexpr
1786bool operator==(const year& __lhs, const year& __rhs) noexcept
1787{ return static_cast<int>(__lhs) == static_cast<int>(__rhs); }
1788
1789inline constexpr
1790bool operator!=(const year& __lhs, const year& __rhs) noexcept
1791{ return !(__lhs == __rhs); }
1792
1793inline constexpr
1794bool operator< (const year& __lhs, const year& __rhs) noexcept
1795{ return static_cast<int>(__lhs)  < static_cast<int>(__rhs); }
1796
1797inline constexpr
1798bool operator> (const year& __lhs, const year& __rhs) noexcept
1799{ return __rhs < __lhs; }
1800
1801inline constexpr
1802bool operator<=(const year& __lhs, const year& __rhs) noexcept
1803{ return !(__rhs < __lhs); }
1804
1805inline constexpr
1806bool operator>=(const year& __lhs, const year& __rhs) noexcept
1807{ return !(__lhs < __rhs); }
1808
1809inline constexpr
1810year operator+ (const year& __lhs, const years& __rhs) noexcept
1811{ return year(static_cast<int>(__lhs) + __rhs.count()); }
1812
1813inline constexpr
1814year operator+ (const years& __lhs, const year& __rhs) noexcept
1815{ return __rhs + __lhs; }
1816
1817inline constexpr
1818year operator- (const year& __lhs, const years& __rhs) noexcept
1819{ return __lhs + -__rhs; }
1820
1821inline constexpr
1822years operator-(const year& __lhs, const year& __rhs) noexcept
1823{ return years{static_cast<int>(__lhs) - static_cast<int>(__rhs)}; }
1824
1825
1826inline constexpr year& year::operator+=(const years& __dy) noexcept
1827{ *this = *this + __dy; return *this; }
1828
1829inline constexpr year& year::operator-=(const years& __dy) noexcept
1830{ *this = *this - __dy; return *this; }
1831
1832inline constexpr bool year::ok() const noexcept
1833{ return static_cast<int>(min()) <= __y && __y <= static_cast<int>(max()); }
1834
1835class weekday_indexed;
1836class weekday_last;
1837
1838class weekday {
1839private:
1840    unsigned char __wd;
1841public:
1842  weekday() = default;
1843  inline explicit constexpr weekday(unsigned __val) noexcept : __wd(static_cast<unsigned char>(__val == 7 ? 0 : __val)) {}
1844  inline constexpr          weekday(const sys_days& __sysd) noexcept
1845          : __wd(__weekday_from_days(__sysd.time_since_epoch().count())) {}
1846  inline explicit constexpr weekday(const local_days& __locd) noexcept
1847          : __wd(__weekday_from_days(__locd.time_since_epoch().count())) {}
1848
1849  inline constexpr weekday& operator++()    noexcept { __wd = (__wd == 6 ? 0 : __wd + 1); return *this; }
1850  inline constexpr weekday  operator++(int) noexcept { weekday __tmp = *this; ++(*this); return __tmp; }
1851  inline constexpr weekday& operator--()    noexcept { __wd = (__wd == 0 ? 6 : __wd - 1); return *this; }
1852  inline constexpr weekday  operator--(int) noexcept { weekday __tmp = *this; --(*this); return __tmp; }
1853         constexpr weekday& operator+=(const days& __dd) noexcept;
1854         constexpr weekday& operator-=(const days& __dd) noexcept;
1855  inline constexpr unsigned c_encoding()   const noexcept { return __wd; }
1856  inline constexpr unsigned iso_encoding() const noexcept { return __wd == 0u ? 7 : __wd; }
1857  inline constexpr bool ok() const noexcept { return __wd <= 6; }
1858         constexpr weekday_indexed operator[](unsigned __index) const noexcept;
1859         constexpr weekday_last    operator[](last_spec) const noexcept;
1860
1861  // TODO: Make private?
1862  static constexpr unsigned char __weekday_from_days(int __days) noexcept;
1863};
1864
1865
1866// https://howardhinnant.github.io/date_algorithms.html#weekday_from_days
1867inline constexpr
1868unsigned char weekday::__weekday_from_days(int __days) noexcept
1869{
1870    return static_cast<unsigned char>(
1871              static_cast<unsigned>(__days >= -4 ? (__days+4) % 7 : (__days+5) % 7 + 6)
1872           );
1873}
1874
1875inline constexpr
1876bool operator==(const weekday& __lhs, const weekday& __rhs) noexcept
1877{ return __lhs.c_encoding() == __rhs.c_encoding(); }
1878
1879inline constexpr
1880bool operator!=(const weekday& __lhs, const weekday& __rhs) noexcept
1881{ return !(__lhs == __rhs); }
1882
1883inline constexpr
1884bool operator< (const weekday& __lhs, const weekday& __rhs) noexcept
1885{ return __lhs.c_encoding() < __rhs.c_encoding(); }
1886
1887inline constexpr
1888bool operator> (const weekday& __lhs, const weekday& __rhs) noexcept
1889{ return __rhs < __lhs; }
1890
1891inline constexpr
1892bool operator<=(const weekday& __lhs, const weekday& __rhs) noexcept
1893{ return !(__rhs < __lhs);}
1894
1895inline constexpr
1896bool operator>=(const weekday& __lhs, const weekday& __rhs) noexcept
1897{ return !(__lhs < __rhs); }
1898
1899constexpr weekday operator+(const weekday& __lhs, const days& __rhs) noexcept
1900{
1901    auto const __mu = static_cast<long long>(__lhs.c_encoding()) + __rhs.count();
1902    auto const __yr = (__mu >= 0 ? __mu : __mu - 6) / 7;
1903    return weekday{static_cast<unsigned>(__mu - __yr * 7)};
1904}
1905
1906constexpr weekday operator+(const days& __lhs, const weekday& __rhs) noexcept
1907{ return __rhs + __lhs; }
1908
1909constexpr weekday operator-(const weekday& __lhs, const days& __rhs) noexcept
1910{ return __lhs + -__rhs; }
1911
1912constexpr days operator-(const weekday& __lhs, const weekday& __rhs) noexcept
1913{
1914    const int __wdu = __lhs.c_encoding() - __rhs.c_encoding();
1915    const int __wk = (__wdu >= 0 ? __wdu : __wdu-6) / 7;
1916    return days{__wdu - __wk * 7};
1917}
1918
1919inline constexpr weekday& weekday::operator+=(const days& __dd) noexcept
1920{ *this = *this + __dd; return *this; }
1921
1922inline constexpr weekday& weekday::operator-=(const days& __dd) noexcept
1923{ *this = *this - __dd; return *this; }
1924
1925
1926class weekday_indexed {
1927private:
1928    _VSTD::chrono::weekday __wd;
1929    unsigned char          __idx;
1930public:
1931    weekday_indexed() = default;
1932    inline constexpr weekday_indexed(const _VSTD::chrono::weekday& __wdval, unsigned __idxval) noexcept
1933        : __wd{__wdval}, __idx(__idxval) {}
1934    inline constexpr _VSTD::chrono::weekday weekday() const noexcept { return __wd; }
1935    inline constexpr unsigned                 index() const noexcept { return __idx; }
1936    inline constexpr bool ok() const noexcept { return __wd.ok() && __idx >= 1 && __idx <= 5; }
1937};
1938
1939inline constexpr
1940bool operator==(const weekday_indexed& __lhs, const weekday_indexed& __rhs) noexcept
1941{ return __lhs.weekday() == __rhs.weekday() && __lhs.index() == __rhs.index(); }
1942
1943inline constexpr
1944bool operator!=(const weekday_indexed& __lhs, const weekday_indexed& __rhs) noexcept
1945{ return !(__lhs == __rhs); }
1946
1947
1948class weekday_last {
1949private:
1950    _VSTD::chrono::weekday __wd;
1951public:
1952    explicit constexpr weekday_last(const _VSTD::chrono::weekday& __val) noexcept
1953        : __wd{__val} {}
1954    constexpr _VSTD::chrono::weekday weekday() const noexcept { return __wd; }
1955    constexpr bool ok() const noexcept { return __wd.ok(); }
1956};
1957
1958inline constexpr
1959bool operator==(const weekday_last& __lhs, const weekday_last& __rhs) noexcept
1960{ return __lhs.weekday() == __rhs.weekday(); }
1961
1962inline constexpr
1963bool operator!=(const weekday_last& __lhs, const weekday_last& __rhs) noexcept
1964{ return !(__lhs == __rhs); }
1965
1966inline constexpr
1967weekday_indexed weekday::operator[](unsigned __index) const noexcept { return weekday_indexed{*this, __index}; }
1968
1969inline constexpr
1970weekday_last    weekday::operator[](last_spec) const noexcept { return weekday_last{*this}; }
1971
1972
1973inline constexpr last_spec last{};
1974inline constexpr weekday   Sunday{0};
1975inline constexpr weekday   Monday{1};
1976inline constexpr weekday   Tuesday{2};
1977inline constexpr weekday   Wednesday{3};
1978inline constexpr weekday   Thursday{4};
1979inline constexpr weekday   Friday{5};
1980inline constexpr weekday   Saturday{6};
1981
1982inline constexpr month January{1};
1983inline constexpr month February{2};
1984inline constexpr month March{3};
1985inline constexpr month April{4};
1986inline constexpr month May{5};
1987inline constexpr month June{6};
1988inline constexpr month July{7};
1989inline constexpr month August{8};
1990inline constexpr month September{9};
1991inline constexpr month October{10};
1992inline constexpr month November{11};
1993inline constexpr month December{12};
1994
1995
1996class month_day {
1997private:
1998   chrono::month __m;
1999   chrono::day   __d;
2000public:
2001    month_day() = default;
2002    constexpr month_day(const chrono::month& __mval, const chrono::day& __dval) noexcept
2003        : __m{__mval}, __d{__dval} {}
2004    inline constexpr chrono::month month() const noexcept { return __m; }
2005    inline constexpr chrono::day   day()   const noexcept { return __d; }
2006    constexpr bool ok() const noexcept;
2007};
2008
2009inline constexpr
2010bool month_day::ok() const noexcept
2011{
2012    if (!__m.ok()) return false;
2013    const unsigned __dval = static_cast<unsigned>(__d);
2014    if (__dval < 1 || __dval > 31) return false;
2015    if (__dval <= 29) return true;
2016//  Now we've got either 30 or 31
2017    const unsigned __mval = static_cast<unsigned>(__m);
2018    if (__mval == 2) return false;
2019    if (__mval == 4 || __mval == 6 || __mval == 9 || __mval == 11)
2020        return __dval == 30;
2021    return true;
2022}
2023
2024inline constexpr
2025bool operator==(const month_day& __lhs, const month_day& __rhs) noexcept
2026{ return __lhs.month() == __rhs.month() && __lhs.day() == __rhs.day(); }
2027
2028inline constexpr
2029bool operator!=(const month_day& __lhs, const month_day& __rhs) noexcept
2030{ return !(__lhs == __rhs); }
2031
2032inline constexpr
2033month_day operator/(const month& __lhs, const day& __rhs) noexcept
2034{ return month_day{__lhs, __rhs}; }
2035
2036constexpr
2037month_day operator/(const day& __lhs, const month& __rhs) noexcept
2038{ return __rhs / __lhs; }
2039
2040inline constexpr
2041month_day operator/(const month& __lhs, int __rhs) noexcept
2042{ return __lhs / day(__rhs); }
2043
2044constexpr
2045month_day operator/(int __lhs, const day& __rhs) noexcept
2046{ return month(__lhs) / __rhs; }
2047
2048constexpr
2049month_day operator/(const day& __lhs, int __rhs) noexcept
2050{ return month(__rhs) / __lhs; }
2051
2052
2053inline constexpr
2054bool operator< (const month_day& __lhs, const month_day& __rhs) noexcept
2055{ return __lhs.month() != __rhs.month() ? __lhs.month() < __rhs.month() : __lhs.day() < __rhs.day(); }
2056
2057inline constexpr
2058bool operator> (const month_day& __lhs, const month_day& __rhs) noexcept
2059{ return __rhs < __lhs; }
2060
2061inline constexpr
2062bool operator<=(const month_day& __lhs, const month_day& __rhs) noexcept
2063{ return !(__rhs < __lhs);}
2064
2065inline constexpr
2066bool operator>=(const month_day& __lhs, const month_day& __rhs) noexcept
2067{ return !(__lhs < __rhs); }
2068
2069
2070
2071class month_day_last {
2072private:
2073    chrono::month __m;
2074public:
2075    explicit constexpr month_day_last(const chrono::month& __val) noexcept
2076        : __m{__val} {}
2077    inline constexpr chrono::month month() const noexcept { return __m; }
2078    inline constexpr bool ok() const noexcept { return __m.ok(); }
2079};
2080
2081inline constexpr
2082bool operator==(const month_day_last& __lhs, const month_day_last& __rhs) noexcept
2083{ return __lhs.month() == __rhs.month(); }
2084
2085inline constexpr
2086bool operator!=(const month_day_last& __lhs, const month_day_last& __rhs) noexcept
2087{ return !(__lhs == __rhs); }
2088
2089inline constexpr
2090bool operator< (const month_day_last& __lhs, const month_day_last& __rhs) noexcept
2091{ return __lhs.month() < __rhs.month(); }
2092
2093inline constexpr
2094bool operator> (const month_day_last& __lhs, const month_day_last& __rhs) noexcept
2095{ return __rhs < __lhs; }
2096
2097inline constexpr
2098bool operator<=(const month_day_last& __lhs, const month_day_last& __rhs) noexcept
2099{ return !(__rhs < __lhs);}
2100
2101inline constexpr
2102bool operator>=(const month_day_last& __lhs, const month_day_last& __rhs) noexcept
2103{ return !(__lhs < __rhs); }
2104
2105inline constexpr
2106month_day_last operator/(const month& __lhs, last_spec) noexcept
2107{ return month_day_last{__lhs}; }
2108
2109inline constexpr
2110month_day_last operator/(last_spec, const month& __rhs) noexcept
2111{ return month_day_last{__rhs}; }
2112
2113inline constexpr
2114month_day_last operator/(int __lhs, last_spec) noexcept
2115{ return month_day_last{month(__lhs)}; }
2116
2117inline constexpr
2118month_day_last operator/(last_spec, int __rhs) noexcept
2119{ return month_day_last{month(__rhs)}; }
2120
2121
2122class month_weekday {
2123private:
2124    chrono::month __m;
2125    chrono::weekday_indexed __wdi;
2126public:
2127    month_weekday() = default;
2128    constexpr month_weekday(const chrono::month& __mval, const chrono::weekday_indexed& __wdival) noexcept
2129        : __m{__mval}, __wdi{__wdival} {}
2130    inline constexpr chrono::month                     month() const noexcept { return __m; }
2131    inline constexpr chrono::weekday_indexed weekday_indexed() const noexcept { return __wdi; }
2132    inline constexpr bool                                 ok() const noexcept { return __m.ok() && __wdi.ok(); }
2133};
2134
2135inline constexpr
2136bool operator==(const month_weekday& __lhs, const month_weekday& __rhs) noexcept
2137{ return __lhs.month() == __rhs.month() && __lhs.weekday_indexed() == __rhs.weekday_indexed(); }
2138
2139inline constexpr
2140bool operator!=(const month_weekday& __lhs, const month_weekday& __rhs) noexcept
2141{ return !(__lhs == __rhs); }
2142
2143inline constexpr
2144month_weekday operator/(const month& __lhs, const weekday_indexed& __rhs) noexcept
2145{ return month_weekday{__lhs, __rhs}; }
2146
2147inline constexpr
2148month_weekday operator/(int __lhs, const weekday_indexed& __rhs) noexcept
2149{ return month_weekday{month(__lhs), __rhs}; }
2150
2151inline constexpr
2152month_weekday operator/(const weekday_indexed& __lhs, const month& __rhs) noexcept
2153{ return month_weekday{__rhs, __lhs}; }
2154
2155inline constexpr
2156month_weekday operator/(const weekday_indexed& __lhs, int __rhs) noexcept
2157{ return month_weekday{month(__rhs), __lhs}; }
2158
2159
2160class month_weekday_last {
2161    chrono::month        __m;
2162    chrono::weekday_last __wdl;
2163  public:
2164    constexpr month_weekday_last(const chrono::month& __mval, const chrono::weekday_last& __wdlval) noexcept
2165        : __m{__mval}, __wdl{__wdlval} {}
2166    inline constexpr chrono::month               month() const noexcept { return __m; }
2167    inline constexpr chrono::weekday_last weekday_last() const noexcept { return __wdl; }
2168    inline constexpr bool                           ok() const noexcept { return __m.ok() && __wdl.ok(); }
2169};
2170
2171inline constexpr
2172bool operator==(const month_weekday_last& __lhs, const month_weekday_last& __rhs) noexcept
2173{ return __lhs.month() == __rhs.month() && __lhs.weekday_last() == __rhs.weekday_last(); }
2174
2175inline constexpr
2176bool operator!=(const month_weekday_last& __lhs, const month_weekday_last& __rhs) noexcept
2177{ return !(__lhs == __rhs); }
2178
2179
2180inline constexpr
2181month_weekday_last operator/(const month& __lhs, const weekday_last& __rhs) noexcept
2182{ return month_weekday_last{__lhs, __rhs}; }
2183
2184inline constexpr
2185month_weekday_last operator/(int __lhs, const weekday_last& __rhs) noexcept
2186{ return month_weekday_last{month(__lhs), __rhs}; }
2187
2188inline constexpr
2189month_weekday_last operator/(const weekday_last& __lhs, const month& __rhs) noexcept
2190{ return month_weekday_last{__rhs, __lhs}; }
2191
2192inline constexpr
2193month_weekday_last operator/(const weekday_last& __lhs, int __rhs) noexcept
2194{ return month_weekday_last{month(__rhs), __lhs}; }
2195
2196
2197class year_month {
2198    chrono::year  __y;
2199    chrono::month __m;
2200public:
2201    year_month() = default;
2202    constexpr year_month(const chrono::year& __yval, const chrono::month& __mval) noexcept
2203        : __y{__yval}, __m{__mval} {}
2204    inline constexpr chrono::year  year()  const noexcept { return __y; }
2205    inline constexpr chrono::month month() const noexcept { return __m; }
2206    inline constexpr year_month& operator+=(const months& __dm) noexcept { this->__m += __dm; return *this; }
2207    inline constexpr year_month& operator-=(const months& __dm) noexcept { this->__m -= __dm; return *this; }
2208    inline constexpr year_month& operator+=(const years& __dy)  noexcept { this->__y += __dy; return *this; }
2209    inline constexpr year_month& operator-=(const years& __dy)  noexcept { this->__y -= __dy; return *this; }
2210    inline constexpr bool ok() const noexcept { return __y.ok() && __m.ok(); }
2211};
2212
2213inline constexpr
2214year_month operator/(const year& __y, const month& __m) noexcept { return year_month{__y, __m}; }
2215
2216inline constexpr
2217year_month operator/(const year& __y, int __m) noexcept { return year_month{__y, month(__m)}; }
2218
2219inline constexpr
2220bool operator==(const year_month& __lhs, const year_month& __rhs) noexcept
2221{ return __lhs.year() == __rhs.year() && __lhs.month() == __rhs.month(); }
2222
2223inline constexpr
2224bool operator!=(const year_month& __lhs, const year_month& __rhs) noexcept
2225{ return !(__lhs == __rhs); }
2226
2227inline constexpr
2228bool operator< (const year_month& __lhs, const year_month& __rhs) noexcept
2229{ return __lhs.year() != __rhs.year() ? __lhs.year() < __rhs.year() : __lhs.month() < __rhs.month(); }
2230
2231inline constexpr
2232bool operator> (const year_month& __lhs, const year_month& __rhs) noexcept
2233{ return __rhs < __lhs; }
2234
2235inline constexpr
2236bool operator<=(const year_month& __lhs, const year_month& __rhs) noexcept
2237{ return !(__rhs < __lhs);}
2238
2239inline constexpr
2240bool operator>=(const year_month& __lhs, const year_month& __rhs) noexcept
2241{ return !(__lhs < __rhs); }
2242
2243constexpr year_month operator+(const year_month& __lhs, const months& __rhs) noexcept
2244{
2245    int __dmi = static_cast<int>(static_cast<unsigned>(__lhs.month())) - 1 + __rhs.count();
2246    const int __dy = (__dmi >= 0 ? __dmi : __dmi-11) / 12;
2247    __dmi = __dmi - __dy * 12 + 1;
2248    return (__lhs.year() + years(__dy)) / month(static_cast<unsigned>(__dmi));
2249}
2250
2251constexpr year_month operator+(const months& __lhs, const year_month& __rhs) noexcept
2252{ return __rhs + __lhs; }
2253
2254constexpr year_month operator+(const year_month& __lhs, const years& __rhs) noexcept
2255{ return (__lhs.year() + __rhs) / __lhs.month(); }
2256
2257constexpr year_month operator+(const years& __lhs, const year_month& __rhs) noexcept
2258{ return __rhs + __lhs; }
2259
2260constexpr months     operator-(const year_month& __lhs, const year_month& __rhs) noexcept
2261{ return (__lhs.year() - __rhs.year()) + months(static_cast<unsigned>(__lhs.month()) - static_cast<unsigned>(__rhs.month())); }
2262
2263constexpr year_month operator-(const year_month& __lhs, const months& __rhs) noexcept
2264{ return __lhs + -__rhs; }
2265
2266constexpr year_month operator-(const year_month& __lhs, const years& __rhs) noexcept
2267{ return __lhs + -__rhs; }
2268
2269class year_month_day_last;
2270
2271class year_month_day {
2272private:
2273    chrono::year  __y;
2274    chrono::month __m;
2275    chrono::day   __d;
2276public:
2277     year_month_day() = default;
2278     inline constexpr year_month_day(
2279            const chrono::year& __yval, const chrono::month& __mval, const chrono::day& __dval) noexcept
2280            : __y{__yval}, __m{__mval}, __d{__dval} {}
2281            constexpr year_month_day(const year_month_day_last& __ymdl) noexcept;
2282     inline constexpr year_month_day(const sys_days& __sysd) noexcept
2283            : year_month_day(__from_days(__sysd.time_since_epoch())) {}
2284     inline explicit constexpr year_month_day(const local_days& __locd) noexcept
2285            : year_month_day(__from_days(__locd.time_since_epoch())) {}
2286
2287            constexpr year_month_day& operator+=(const months& __dm) noexcept;
2288            constexpr year_month_day& operator-=(const months& __dm) noexcept;
2289            constexpr year_month_day& operator+=(const years& __dy)  noexcept;
2290            constexpr year_month_day& operator-=(const years& __dy)  noexcept;
2291
2292     inline constexpr chrono::year   year() const noexcept { return __y; }
2293     inline constexpr chrono::month month() const noexcept { return __m; }
2294     inline constexpr chrono::day     day() const noexcept { return __d; }
2295     inline constexpr operator   sys_days() const noexcept          { return   sys_days{__to_days()}; }
2296     inline explicit constexpr operator local_days() const noexcept { return local_days{__to_days()}; }
2297
2298            constexpr bool             ok() const noexcept;
2299
2300     static constexpr year_month_day __from_days(days __d) noexcept;
2301     constexpr days __to_days() const noexcept;
2302};
2303
2304
2305// https://howardhinnant.github.io/date_algorithms.html#civil_from_days
2306inline constexpr
2307year_month_day
2308year_month_day::__from_days(days __d) noexcept
2309{
2310    static_assert(std::numeric_limits<unsigned>::digits >= 18, "");
2311    static_assert(std::numeric_limits<int>::digits >= 20     , "");
2312    const int      __z = __d.count() + 719468;
2313    const int      __era = (__z >= 0 ? __z : __z - 146096) / 146097;
2314    const unsigned __doe = static_cast<unsigned>(__z - __era * 146097);              // [0, 146096]
2315    const unsigned __yoe = (__doe - __doe/1460 + __doe/36524 - __doe/146096) / 365;  // [0, 399]
2316    const int      __yr = static_cast<int>(__yoe) + __era * 400;
2317    const unsigned __doy = __doe - (365 * __yoe + __yoe/4 - __yoe/100);              // [0, 365]
2318    const unsigned __mp = (5 * __doy + 2)/153;                                       // [0, 11]
2319    const unsigned __dy = __doy - (153 * __mp + 2)/5 + 1;                            // [1, 31]
2320    const unsigned __mth = __mp + (__mp < 10 ? 3 : -9);                              // [1, 12]
2321    return year_month_day{chrono::year{__yr + (__mth <= 2)}, chrono::month{__mth}, chrono::day{__dy}};
2322}
2323
2324// https://howardhinnant.github.io/date_algorithms.html#days_from_civil
2325inline constexpr days year_month_day::__to_days() const noexcept
2326{
2327    static_assert(std::numeric_limits<unsigned>::digits >= 18, "");
2328    static_assert(std::numeric_limits<int>::digits >= 20     , "");
2329
2330    const int      __yr  = static_cast<int>(__y) - (__m <= February);
2331    const unsigned __mth = static_cast<unsigned>(__m);
2332    const unsigned __dy  = static_cast<unsigned>(__d);
2333
2334    const int      __era = (__yr >= 0 ? __yr : __yr - 399) / 400;
2335    const unsigned __yoe = static_cast<unsigned>(__yr - __era * 400);                // [0, 399]
2336    const unsigned __doy = (153 * (__mth + (__mth > 2 ? -3 : 9)) + 2) / 5 + __dy-1;  // [0, 365]
2337    const unsigned __doe = __yoe * 365 + __yoe/4 - __yoe/100 + __doy;                // [0, 146096]
2338    return days{__era * 146097 + static_cast<int>(__doe) - 719468};
2339}
2340
2341inline constexpr
2342bool operator==(const year_month_day& __lhs, const year_month_day& __rhs) noexcept
2343{ return __lhs.year() == __rhs.year() && __lhs.month() == __rhs.month() && __lhs.day() == __rhs.day(); }
2344
2345inline constexpr
2346bool operator!=(const year_month_day& __lhs, const year_month_day& __rhs) noexcept
2347{ return !(__lhs == __rhs); }
2348
2349inline constexpr
2350bool operator< (const year_month_day& __lhs, const year_month_day& __rhs) noexcept
2351{
2352    if (__lhs.year() < __rhs.year()) return true;
2353    if (__lhs.year() > __rhs.year()) return false;
2354    if (__lhs.month() < __rhs.month()) return true;
2355    if (__lhs.month() > __rhs.month()) return false;
2356    return __lhs.day() < __rhs.day();
2357}
2358
2359inline constexpr
2360bool operator> (const year_month_day& __lhs, const year_month_day& __rhs) noexcept
2361{ return __rhs < __lhs; }
2362
2363inline constexpr
2364bool operator<=(const year_month_day& __lhs, const year_month_day& __rhs) noexcept
2365{ return !(__rhs < __lhs);}
2366
2367inline constexpr
2368bool operator>=(const year_month_day& __lhs, const year_month_day& __rhs) noexcept
2369{ return !(__lhs < __rhs); }
2370
2371inline constexpr
2372year_month_day operator/(const year_month& __lhs, const day& __rhs) noexcept
2373{ return year_month_day{__lhs.year(), __lhs.month(), __rhs}; }
2374
2375inline constexpr
2376year_month_day operator/(const year_month& __lhs, int __rhs) noexcept
2377{ return __lhs / day(__rhs); }
2378
2379inline constexpr
2380year_month_day operator/(const year& __lhs, const month_day& __rhs) noexcept
2381{ return __lhs / __rhs.month() / __rhs.day(); }
2382
2383inline constexpr
2384year_month_day operator/(int __lhs, const month_day& __rhs) noexcept
2385{ return year(__lhs) / __rhs; }
2386
2387inline constexpr
2388year_month_day operator/(const month_day& __lhs, const year& __rhs) noexcept
2389{ return __rhs / __lhs; }
2390
2391inline constexpr
2392year_month_day operator/(const month_day& __lhs, int __rhs) noexcept
2393{ return year(__rhs) / __lhs; }
2394
2395
2396inline constexpr
2397year_month_day operator+(const year_month_day& __lhs, const months& __rhs) noexcept
2398{ return (__lhs.year()/__lhs.month() + __rhs)/__lhs.day(); }
2399
2400inline constexpr
2401year_month_day operator+(const months& __lhs, const year_month_day& __rhs) noexcept
2402{ return __rhs + __lhs; }
2403
2404inline constexpr
2405year_month_day operator-(const year_month_day& __lhs, const months& __rhs) noexcept
2406{ return __lhs + -__rhs; }
2407
2408inline constexpr
2409year_month_day operator+(const year_month_day& __lhs, const years& __rhs) noexcept
2410{ return (__lhs.year() + __rhs) / __lhs.month() / __lhs.day(); }
2411
2412inline constexpr
2413year_month_day operator+(const years& __lhs, const year_month_day& __rhs) noexcept
2414{ return __rhs + __lhs; }
2415
2416inline constexpr
2417year_month_day operator-(const year_month_day& __lhs, const years& __rhs) noexcept
2418{ return __lhs + -__rhs; }
2419
2420inline constexpr year_month_day& year_month_day::operator+=(const months& __dm) noexcept { *this = *this + __dm; return *this; }
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 years& __dy)  noexcept { *this = *this + __dy; return *this; }
2423inline constexpr year_month_day& year_month_day::operator-=(const years& __dy)  noexcept { *this = *this - __dy; return *this; }
2424
2425class year_month_day_last {
2426private:
2427    chrono::year           __y;
2428    chrono::month_day_last __mdl;
2429public:
2430     constexpr year_month_day_last(const year& __yval, const month_day_last& __mdlval) noexcept
2431        : __y{__yval}, __mdl{__mdlval} {}
2432
2433     constexpr year_month_day_last& operator+=(const months& __m) noexcept;
2434     constexpr year_month_day_last& operator-=(const months& __m) noexcept;
2435     constexpr year_month_day_last& operator+=(const years& __y)  noexcept;
2436     constexpr year_month_day_last& operator-=(const years& __y)  noexcept;
2437
2438     inline constexpr chrono::year                     year() const noexcept { return __y; }
2439     inline constexpr chrono::month                   month() const noexcept { return __mdl.month(); }
2440     inline constexpr chrono::month_day_last month_day_last() const noexcept { return __mdl; }
2441            constexpr chrono::day                       day() const noexcept;
2442     inline constexpr operator                     sys_days() const noexcept { return   sys_days{year()/month()/day()}; }
2443     inline explicit constexpr operator          local_days() const noexcept { return local_days{year()/month()/day()}; }
2444     inline constexpr bool                               ok() const noexcept { return __y.ok() && __mdl.ok(); }
2445};
2446
2447inline constexpr
2448chrono::day year_month_day_last::day() const noexcept
2449{
2450    constexpr chrono::day __d[] =
2451    {
2452        chrono::day(31), chrono::day(28), chrono::day(31),
2453        chrono::day(30), chrono::day(31), chrono::day(30),
2454        chrono::day(31), chrono::day(31), chrono::day(30),
2455        chrono::day(31), chrono::day(30), chrono::day(31)
2456    };
2457    return month() != February || !__y.is_leap() ?
2458        __d[static_cast<unsigned>(month()) - 1] : chrono::day{29};
2459}
2460
2461inline constexpr
2462bool operator==(const year_month_day_last& __lhs, const year_month_day_last& __rhs) noexcept
2463{ return __lhs.year() == __rhs.year() && __lhs.month_day_last() == __rhs.month_day_last(); }
2464
2465inline constexpr
2466bool operator!=(const year_month_day_last& __lhs, const year_month_day_last& __rhs) noexcept
2467{ return !(__lhs == __rhs); }
2468
2469inline constexpr
2470bool operator< (const year_month_day_last& __lhs, const year_month_day_last& __rhs) noexcept
2471{
2472    if (__lhs.year() < __rhs.year()) return true;
2473    if (__lhs.year() > __rhs.year()) return false;
2474    return __lhs.month_day_last() < __rhs.month_day_last();
2475}
2476
2477inline constexpr
2478bool operator> (const year_month_day_last& __lhs, const year_month_day_last& __rhs) noexcept
2479{ return __rhs < __lhs; }
2480
2481inline constexpr
2482bool operator<=(const year_month_day_last& __lhs, const year_month_day_last& __rhs) noexcept
2483{ return !(__rhs < __lhs);}
2484
2485inline constexpr
2486bool operator>=(const year_month_day_last& __lhs, const year_month_day_last& __rhs) noexcept
2487{ return !(__lhs < __rhs); }
2488
2489inline constexpr year_month_day_last operator/(const year_month& __lhs, last_spec) noexcept
2490{ return year_month_day_last{__lhs.year(), month_day_last{__lhs.month()}}; }
2491
2492inline constexpr year_month_day_last operator/(const year& __lhs, const month_day_last& __rhs) noexcept
2493{ return year_month_day_last{__lhs, __rhs}; }
2494
2495inline constexpr year_month_day_last operator/(int __lhs, const month_day_last& __rhs) noexcept
2496{ return year_month_day_last{year{__lhs}, __rhs}; }
2497
2498inline constexpr year_month_day_last operator/(const month_day_last& __lhs, const year& __rhs) noexcept
2499{ return __rhs / __lhs; }
2500
2501inline constexpr year_month_day_last operator/(const month_day_last& __lhs, int __rhs) noexcept
2502{ return year{__rhs} / __lhs; }
2503
2504
2505inline constexpr
2506year_month_day_last operator+(const year_month_day_last& __lhs, const months& __rhs) noexcept
2507{ return (__lhs.year() / __lhs.month() + __rhs) / last; }
2508
2509inline constexpr
2510year_month_day_last operator+(const months& __lhs, const year_month_day_last& __rhs) noexcept
2511{ return __rhs + __lhs; }
2512
2513inline constexpr
2514year_month_day_last operator-(const year_month_day_last& __lhs, const months& __rhs) noexcept
2515{ return __lhs + (-__rhs); }
2516
2517inline constexpr
2518year_month_day_last operator+(const year_month_day_last& __lhs, const years& __rhs) noexcept
2519{ return year_month_day_last{__lhs.year() + __rhs, __lhs.month_day_last()}; }
2520
2521inline constexpr
2522year_month_day_last operator+(const years& __lhs, const year_month_day_last& __rhs) noexcept
2523{ return __rhs + __lhs; }
2524
2525inline constexpr
2526year_month_day_last operator-(const year_month_day_last& __lhs, const years& __rhs) noexcept
2527{ return __lhs + (-__rhs); }
2528
2529inline constexpr year_month_day_last& year_month_day_last::operator+=(const months& __dm) noexcept { *this = *this + __dm; return *this; }
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 years& __dy)  noexcept { *this = *this + __dy; return *this; }
2532inline constexpr year_month_day_last& year_month_day_last::operator-=(const years& __dy)  noexcept { *this = *this - __dy; return *this; }
2533
2534inline constexpr year_month_day::year_month_day(const year_month_day_last& __ymdl) noexcept
2535    : __y{__ymdl.year()}, __m{__ymdl.month()}, __d{__ymdl.day()} {}
2536
2537inline constexpr bool year_month_day::ok() const noexcept
2538{
2539    if (!__y.ok() || !__m.ok()) return false;
2540    return chrono::day{1} <= __d && __d <= (__y / __m / last).day();
2541}
2542
2543class year_month_weekday {
2544    chrono::year            __y;
2545    chrono::month           __m;
2546    chrono::weekday_indexed __wdi;
2547public:
2548    year_month_weekday() = default;
2549    constexpr year_month_weekday(const chrono::year& __yval, const chrono::month& __mval,
2550                               const chrono::weekday_indexed& __wdival) noexcept
2551        : __y{__yval}, __m{__mval}, __wdi{__wdival} {}
2552    constexpr year_month_weekday(const sys_days& __sysd) noexcept
2553            : year_month_weekday(__from_days(__sysd.time_since_epoch())) {}
2554    inline explicit constexpr year_month_weekday(const local_days& __locd) noexcept
2555            : year_month_weekday(__from_days(__locd.time_since_epoch())) {}
2556    constexpr year_month_weekday& operator+=(const months& m) noexcept;
2557    constexpr year_month_weekday& operator-=(const months& m) noexcept;
2558    constexpr year_month_weekday& operator+=(const years& y)  noexcept;
2559    constexpr year_month_weekday& operator-=(const years& y)  noexcept;
2560
2561    inline constexpr chrono::year                       year() const noexcept { return __y; }
2562    inline constexpr chrono::month                     month() const noexcept { return __m; }
2563    inline constexpr chrono::weekday                 weekday() const noexcept { return __wdi.weekday(); }
2564    inline constexpr unsigned                          index() const noexcept { return __wdi.index(); }
2565    inline constexpr chrono::weekday_indexed weekday_indexed() const noexcept { return __wdi; }
2566
2567    inline constexpr                       operator sys_days() const noexcept { return   sys_days{__to_days()}; }
2568    inline explicit constexpr operator            local_days() const noexcept { return local_days{__to_days()}; }
2569    inline constexpr bool ok() const noexcept
2570    {
2571        if (!__y.ok() || !__m.ok() || !__wdi.ok()) return false;
2572        if (__wdi.index() <= 4) return true;
2573        auto __nth_weekday_day =
2574            __wdi.weekday() -
2575            chrono::weekday{static_cast<sys_days>(__y / __m / 1)} +
2576            days{(__wdi.index() - 1) * 7 + 1};
2577        return static_cast<unsigned>(__nth_weekday_day.count()) <=
2578               static_cast<unsigned>((__y / __m / last).day());
2579    }
2580
2581    static constexpr year_month_weekday __from_days(days __d) noexcept;
2582    constexpr days __to_days() const noexcept;
2583};
2584
2585inline constexpr
2586year_month_weekday year_month_weekday::__from_days(days __d) noexcept
2587{
2588    const sys_days      __sysd{__d};
2589    const chrono::weekday __wd = chrono::weekday(__sysd);
2590    const year_month_day __ymd = year_month_day(__sysd);
2591    return year_month_weekday{__ymd.year(), __ymd.month(),
2592                              __wd[(static_cast<unsigned>(__ymd.day())-1)/7+1]};
2593}
2594
2595inline constexpr
2596days year_month_weekday::__to_days() const noexcept
2597{
2598    const sys_days __sysd = sys_days(__y/__m/1);
2599    return (__sysd + (__wdi.weekday() - chrono::weekday(__sysd) + days{(__wdi.index()-1)*7}))
2600                .time_since_epoch();
2601}
2602
2603inline constexpr
2604bool operator==(const year_month_weekday& __lhs, const year_month_weekday& __rhs) noexcept
2605{ return __lhs.year() == __rhs.year() && __lhs.month() == __rhs.month() && __lhs.weekday_indexed() == __rhs.weekday_indexed(); }
2606
2607inline constexpr
2608bool operator!=(const year_month_weekday& __lhs, const year_month_weekday& __rhs) noexcept
2609{ return !(__lhs == __rhs); }
2610
2611inline constexpr
2612year_month_weekday operator/(const year_month& __lhs, const weekday_indexed& __rhs) noexcept
2613{ return year_month_weekday{__lhs.year(), __lhs.month(), __rhs}; }
2614
2615inline constexpr
2616year_month_weekday operator/(const year& __lhs, const month_weekday& __rhs) noexcept
2617{ return year_month_weekday{__lhs, __rhs.month(), __rhs.weekday_indexed()}; }
2618
2619inline constexpr
2620year_month_weekday operator/(int __lhs, const month_weekday& __rhs) noexcept
2621{ return year(__lhs) / __rhs; }
2622
2623inline constexpr
2624year_month_weekday operator/(const month_weekday& __lhs, const year& __rhs) noexcept
2625{ return __rhs / __lhs; }
2626
2627inline constexpr
2628year_month_weekday operator/(const month_weekday& __lhs, int __rhs) noexcept
2629{ return year(__rhs) / __lhs; }
2630
2631
2632inline constexpr
2633year_month_weekday operator+(const year_month_weekday& __lhs, const months& __rhs) noexcept
2634{ return (__lhs.year() / __lhs.month() + __rhs) / __lhs.weekday_indexed(); }
2635
2636inline constexpr
2637year_month_weekday operator+(const months& __lhs, const year_month_weekday& __rhs) noexcept
2638{ return __rhs + __lhs; }
2639
2640inline constexpr
2641year_month_weekday operator-(const year_month_weekday& __lhs, const months& __rhs) noexcept
2642{ return __lhs + (-__rhs); }
2643
2644inline constexpr
2645year_month_weekday operator+(const year_month_weekday& __lhs, const years& __rhs) noexcept
2646{ return year_month_weekday{__lhs.year() + __rhs, __lhs.month(), __lhs.weekday_indexed()}; }
2647
2648inline constexpr
2649year_month_weekday operator+(const years& __lhs, const year_month_weekday& __rhs) noexcept
2650{ return __rhs + __lhs; }
2651
2652inline constexpr
2653year_month_weekday operator-(const year_month_weekday& __lhs, const years& __rhs) noexcept
2654{ return __lhs + (-__rhs); }
2655
2656
2657inline constexpr year_month_weekday& year_month_weekday::operator+=(const months& __dm) noexcept { *this = *this + __dm; return *this; }
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 years& __dy)  noexcept { *this = *this + __dy; return *this; }
2660inline constexpr year_month_weekday& year_month_weekday::operator-=(const years& __dy)  noexcept { *this = *this - __dy; return *this; }
2661
2662class year_month_weekday_last {
2663private:
2664    chrono::year         __y;
2665    chrono::month        __m;
2666    chrono::weekday_last __wdl;
2667public:
2668    constexpr year_month_weekday_last(const chrono::year& __yval, const chrono::month& __mval,
2669                                      const chrono::weekday_last& __wdlval) noexcept
2670                : __y{__yval}, __m{__mval}, __wdl{__wdlval} {}
2671    constexpr year_month_weekday_last& operator+=(const months& __dm) noexcept;
2672    constexpr year_month_weekday_last& operator-=(const months& __dm) noexcept;
2673    constexpr year_month_weekday_last& operator+=(const years& __dy)  noexcept;
2674    constexpr year_month_weekday_last& operator-=(const years& __dy)  noexcept;
2675
2676    inline constexpr chrono::year                 year() const noexcept { return __y; }
2677    inline constexpr chrono::month               month() const noexcept { return __m; }
2678    inline constexpr chrono::weekday           weekday() const noexcept { return __wdl.weekday(); }
2679    inline constexpr chrono::weekday_last weekday_last() const noexcept { return __wdl; }
2680    inline constexpr operator                 sys_days() const noexcept { return   sys_days{__to_days()}; }
2681    inline explicit constexpr operator      local_days() const noexcept { return local_days{__to_days()}; }
2682    inline constexpr bool ok() const noexcept { return __y.ok() && __m.ok() && __wdl.ok(); }
2683
2684    constexpr days __to_days() const noexcept;
2685
2686};
2687
2688inline constexpr
2689days year_month_weekday_last::__to_days() const noexcept
2690{
2691    const sys_days __last = sys_days{__y/__m/last};
2692    return (__last - (chrono::weekday{__last} - __wdl.weekday())).time_since_epoch();
2693
2694}
2695
2696inline constexpr
2697bool operator==(const year_month_weekday_last& __lhs, const year_month_weekday_last& __rhs) noexcept
2698{ return __lhs.year() == __rhs.year() && __lhs.month() == __rhs.month() && __lhs.weekday_last() == __rhs.weekday_last(); }
2699
2700inline constexpr
2701bool operator!=(const year_month_weekday_last& __lhs, const year_month_weekday_last& __rhs) noexcept
2702{ return !(__lhs == __rhs); }
2703
2704
2705inline constexpr
2706year_month_weekday_last operator/(const year_month& __lhs, const weekday_last& __rhs) noexcept
2707{ return year_month_weekday_last{__lhs.year(), __lhs.month(), __rhs}; }
2708
2709inline constexpr
2710year_month_weekday_last operator/(const year& __lhs, const month_weekday_last& __rhs) noexcept
2711{ return year_month_weekday_last{__lhs, __rhs.month(), __rhs.weekday_last()}; }
2712
2713inline constexpr
2714year_month_weekday_last operator/(int __lhs, const month_weekday_last& __rhs) noexcept
2715{ return year(__lhs) / __rhs; }
2716
2717inline constexpr
2718year_month_weekday_last operator/(const month_weekday_last& __lhs, const year& __rhs) noexcept
2719{ return __rhs / __lhs; }
2720
2721inline constexpr
2722year_month_weekday_last operator/(const month_weekday_last& __lhs, int __rhs) noexcept
2723{ return year(__rhs) / __lhs; }
2724
2725
2726inline constexpr
2727year_month_weekday_last operator+(const year_month_weekday_last& __lhs, const months& __rhs) noexcept
2728{ return (__lhs.year() / __lhs.month() + __rhs) / __lhs.weekday_last(); }
2729
2730inline constexpr
2731year_month_weekday_last operator+(const months& __lhs, const year_month_weekday_last& __rhs) noexcept
2732{ return __rhs + __lhs; }
2733
2734inline constexpr
2735year_month_weekday_last operator-(const year_month_weekday_last& __lhs, const months& __rhs) noexcept
2736{ return __lhs + (-__rhs); }
2737
2738inline constexpr
2739year_month_weekday_last operator+(const year_month_weekday_last& __lhs, const years& __rhs) noexcept
2740{ return year_month_weekday_last{__lhs.year() + __rhs, __lhs.month(), __lhs.weekday_last()}; }
2741
2742inline constexpr
2743year_month_weekday_last operator+(const years& __lhs, const year_month_weekday_last& __rhs) noexcept
2744{ return __rhs + __lhs; }
2745
2746inline constexpr
2747year_month_weekday_last operator-(const year_month_weekday_last& __lhs, const years& __rhs) noexcept
2748{ return __lhs + (-__rhs); }
2749
2750inline constexpr year_month_weekday_last& year_month_weekday_last::operator+=(const months& __dm) noexcept { *this = *this + __dm; return *this; }
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 years& __dy)  noexcept { *this = *this + __dy; return *this; }
2753inline constexpr year_month_weekday_last& year_month_weekday_last::operator-=(const years& __dy)  noexcept { *this = *this - __dy; return *this; }
2754
2755
2756template <class _Duration>
2757class hh_mm_ss
2758{
2759private:
2760    static_assert(__is_duration<_Duration>::value, "template parameter of hh_mm_ss must be a std::chrono::duration");
2761    using __CommonType = common_type_t<_Duration, chrono::seconds>;
2762
2763    static constexpr uint64_t __pow10(unsigned __exp)
2764    {
2765        uint64_t __ret = 1;
2766        for (unsigned __i = 0; __i < __exp; ++__i)
2767            __ret *= 10U;
2768        return __ret;
2769    }
2770
2771    static constexpr unsigned __width(uint64_t __n, uint64_t __d = 10, unsigned __w = 0)
2772    {
2773        if (__n >= 2 && __d != 0 && __w < 19)
2774            return 1 + __width(__n, __d % __n * 10, __w+1);
2775        return 0;
2776    }
2777
2778public:
2779    static unsigned constexpr fractional_width = __width(__CommonType::period::den) < 19 ?
2780                                                 __width(__CommonType::period::den) : 6u;
2781    using precision = duration<typename __CommonType::rep, ratio<1, __pow10(fractional_width)>>;
2782
2783    constexpr hh_mm_ss() noexcept : hh_mm_ss{_Duration::zero()} {}
2784
2785    constexpr explicit hh_mm_ss(_Duration __d) noexcept :
2786        __is_neg(__d < _Duration(0)),
2787        __h(duration_cast<chrono::hours>  (abs(__d))),
2788        __m(duration_cast<chrono::minutes>(abs(__d) - hours())),
2789        __s(duration_cast<chrono::seconds>(abs(__d) - hours() - minutes())),
2790        __f(duration_cast<precision>      (abs(__d) - hours() - minutes() - seconds()))
2791        {}
2792
2793    constexpr bool is_negative()        const noexcept { return __is_neg; }
2794    constexpr chrono::hours hours()     const noexcept { return __h; }
2795    constexpr chrono::minutes minutes() const noexcept { return __m; }
2796    constexpr chrono::seconds seconds() const noexcept { return __s; }
2797    constexpr precision subseconds()    const noexcept { return __f; }
2798
2799    constexpr precision to_duration() const noexcept
2800    {
2801        auto __dur = __h + __m + __s + __f;
2802        return __is_neg ? -__dur : __dur;
2803    }
2804
2805    constexpr explicit operator precision() const noexcept { return to_duration(); }
2806
2807private:
2808    bool            __is_neg;
2809    chrono::hours   __h;
2810    chrono::minutes __m;
2811    chrono::seconds __s;
2812    precision       __f;
2813};
2814
2815constexpr bool is_am(const hours& __h) noexcept { return __h >= hours( 0) && __h < hours(12); }
2816constexpr bool is_pm(const hours& __h) noexcept { return __h >= hours(12) && __h < hours(24); }
2817
2818constexpr hours make12(const hours& __h) noexcept
2819{
2820    if      (__h == hours( 0)) return hours(12);
2821    else if (__h <= hours(12)) return __h;
2822    else                       return __h - hours(12);
2823}
2824
2825constexpr hours make24(const hours& __h, bool __is_pm) noexcept
2826{
2827    if (__is_pm)
2828        return __h == hours(12) ? __h : __h + hours(12);
2829    else
2830        return __h == hours(12) ? hours(0) : __h;
2831}
2832
2833#endif // _LIBCPP_STD_VER > 17
2834} // chrono
2835
2836#if _LIBCPP_STD_VER > 11
2837// Suffixes for duration literals [time.duration.literals]
2838inline namespace literals
2839{
2840  inline namespace chrono_literals
2841  {
2842
2843    constexpr chrono::hours operator""h(unsigned long long __h)
2844    {
2845        return chrono::hours(static_cast<chrono::hours::rep>(__h));
2846    }
2847
2848    constexpr chrono::duration<long double, ratio<3600,1>> operator""h(long double __h)
2849    {
2850        return chrono::duration<long double, ratio<3600,1>>(__h);
2851    }
2852
2853
2854    constexpr chrono::minutes operator""min(unsigned long long __m)
2855    {
2856        return chrono::minutes(static_cast<chrono::minutes::rep>(__m));
2857    }
2858
2859    constexpr chrono::duration<long double, ratio<60,1>> operator""min(long double __m)
2860    {
2861        return chrono::duration<long double, ratio<60,1>> (__m);
2862    }
2863
2864
2865    constexpr chrono::seconds operator""s(unsigned long long __s)
2866    {
2867        return chrono::seconds(static_cast<chrono::seconds::rep>(__s));
2868    }
2869
2870    constexpr chrono::duration<long double> operator""s(long double __s)
2871    {
2872        return chrono::duration<long double> (__s);
2873    }
2874
2875
2876    constexpr chrono::milliseconds operator""ms(unsigned long long __ms)
2877    {
2878        return chrono::milliseconds(static_cast<chrono::milliseconds::rep>(__ms));
2879    }
2880
2881    constexpr chrono::duration<long double, milli> operator""ms(long double __ms)
2882    {
2883        return chrono::duration<long double, milli>(__ms);
2884    }
2885
2886
2887    constexpr chrono::microseconds operator""us(unsigned long long __us)
2888    {
2889        return chrono::microseconds(static_cast<chrono::microseconds::rep>(__us));
2890    }
2891
2892    constexpr chrono::duration<long double, micro> operator""us(long double __us)
2893    {
2894        return chrono::duration<long double, micro> (__us);
2895    }
2896
2897
2898    constexpr chrono::nanoseconds operator""ns(unsigned long long __ns)
2899    {
2900        return chrono::nanoseconds(static_cast<chrono::nanoseconds::rep>(__ns));
2901    }
2902
2903    constexpr chrono::duration<long double, nano> operator""ns(long double __ns)
2904    {
2905        return chrono::duration<long double, nano> (__ns);
2906    }
2907
2908#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CXX20_CHRONO_LITERALS)
2909    constexpr chrono::day operator ""d(unsigned long long __d) noexcept
2910    {
2911        return chrono::day(static_cast<unsigned>(__d));
2912    }
2913
2914    constexpr chrono::year operator ""y(unsigned long long __y) noexcept
2915    {
2916        return chrono::year(static_cast<int>(__y));
2917    }
2918#endif
2919}}
2920
2921namespace chrono { // hoist the literals into namespace std::chrono
2922   using namespace literals::chrono_literals;
2923}
2924
2925#endif
2926
2927_LIBCPP_END_NAMESPACE_STD
2928
2929#ifndef _LIBCPP_CXX03_LANG
2930_LIBCPP_BEGIN_NAMESPACE_FILESYSTEM
2931struct _FilesystemClock {
2932#if !defined(_LIBCPP_HAS_NO_INT128)
2933  typedef __int128_t rep;
2934  typedef nano period;
2935#else
2936  typedef long long rep;
2937  typedef nano period;
2938#endif
2939
2940  typedef chrono::duration<rep, period> duration;
2941  typedef chrono::time_point<_FilesystemClock> time_point;
2942
2943  _LIBCPP_EXPORTED_FROM_ABI
2944  static _LIBCPP_CONSTEXPR_AFTER_CXX11 const bool is_steady = false;
2945
2946  _LIBCPP_AVAILABILITY_FILESYSTEM _LIBCPP_FUNC_VIS static time_point now() noexcept;
2947
2948  _LIBCPP_INLINE_VISIBILITY
2949  static time_t to_time_t(const time_point& __t) noexcept {
2950      typedef chrono::duration<rep> __secs;
2951      return time_t(
2952          chrono::duration_cast<__secs>(__t.time_since_epoch()).count());
2953  }
2954
2955  _LIBCPP_INLINE_VISIBILITY
2956  static time_point from_time_t(time_t __t) noexcept {
2957      typedef chrono::duration<rep> __secs;
2958      return time_point(__secs(__t));
2959  }
2960};
2961_LIBCPP_END_NAMESPACE_FILESYSTEM
2962#endif // !_LIBCPP_CXX03_LANG
2963
2964_LIBCPP_POP_MACROS
2965
2966#endif  // _LIBCPP_CHRONO
2967