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1// -*- C++ -*-
2//===---------------------------- chrono ----------------------------------===//
3//
4//                     The LLVM Compiler Infrastructure
5//
6// This file is dual licensed under the MIT and the University of Illinois Open
7// Source Licenses. See LICENSE.TXT for details.
8//
9//===----------------------------------------------------------------------===//
10
11#ifndef _LIBCPP_CHRONO
12#define _LIBCPP_CHRONO
13
14/*
15    chrono synopsis
16
17namespace std
18{
19namespace chrono
20{
21
22template <class ToDuration, class Rep, class Period>
23constexpr
24ToDuration
25duration_cast(const duration<Rep, Period>& fd);
26
27template <class Rep> struct treat_as_floating_point : is_floating_point<Rep> {};
28
29template <class Rep> inline constexpr bool treat_as_floating_point_v
30    = treat_as_floating_point<Rep>::value;                       // C++17
31
32template <class Rep>
33struct duration_values
34{
35public:
36    static constexpr Rep zero(); // noexcept in C++20
37    static constexpr Rep max();  // noexcept in C++20
38    static constexpr Rep min();  // noexcept in C++20
39};
40
41// duration
42
43template <class Rep, class Period = ratio<1>>
44class duration
45{
46    static_assert(!__is_duration<Rep>::value, "A duration representation can not be a duration");
47    static_assert(__is_ratio<Period>::value, "Second template parameter of duration must be a std::ratio");
48    static_assert(Period::num > 0, "duration period must be positive");
49public:
50    typedef Rep rep;
51    typedef typename _Period::type period;
52
53    constexpr duration() = default;
54    template <class Rep2>
55        constexpr explicit duration(const Rep2& r,
56            typename enable_if
57            <
58               is_convertible<Rep2, rep>::value &&
59               (treat_as_floating_point<rep>::value ||
60               !treat_as_floating_point<rep>::value && !treat_as_floating_point<Rep2>::value)
61            >::type* = 0);
62
63    // conversions
64    template <class Rep2, class Period2>
65        constexpr duration(const duration<Rep2, Period2>& d,
66            typename enable_if
67            <
68                treat_as_floating_point<rep>::value ||
69                ratio_divide<Period2, period>::type::den == 1
70            >::type* = 0);
71
72    // observer
73
74    constexpr rep count() const;
75
76    // arithmetic
77
78    constexpr common_type<duration>::type  operator+() const;
79    constexpr common_type<duration>::type  operator-() const;
80    constexpr duration& operator++();    // constexpr in C++17
81    constexpr duration  operator++(int); // constexpr in C++17
82    constexpr duration& operator--();    // constexpr in C++17
83    constexpr duration  operator--(int); // constexpr in C++17
84
85    constexpr duration& operator+=(const duration& d);  // constexpr in C++17
86    constexpr duration& operator-=(const duration& d);  // constexpr in C++17
87
88    duration& operator*=(const rep& rhs);       // constexpr in C++17
89    duration& operator/=(const rep& rhs);       // constexpr in C++17
90    duration& operator%=(const rep& rhs);       // constexpr in C++17
91    duration& operator%=(const duration& rhs);  // constexpr in C++17
92
93    // special values
94
95    static constexpr duration zero(); // noexcept in C++20
96    static constexpr duration min();  // noexcept in C++20
97    static constexpr duration max();  // noexcept in C++20
98};
99
100typedef duration<long long,         nano> nanoseconds;
101typedef duration<long long,        micro> microseconds;
102typedef duration<long long,        milli> milliseconds;
103typedef duration<long long              > seconds;
104typedef duration<     long, ratio<  60> > minutes;
105typedef duration<     long, ratio<3600> > hours;
106
107template <class Clock, class Duration = typename Clock::duration>
108class time_point
109{
110public:
111    typedef Clock                     clock;
112    typedef Duration                  duration;
113    typedef typename duration::rep    rep;
114    typedef typename duration::period period;
115private:
116    duration d_;  // exposition only
117
118public:
119    time_point();  // has value "epoch" // constexpr in C++14
120    explicit time_point(const duration& d);  // same as time_point() + d // constexpr in C++14
121
122    // conversions
123    template <class Duration2>
124       time_point(const time_point<clock, Duration2>& t); // constexpr in C++14
125
126    // observer
127
128    duration time_since_epoch() const; // constexpr in C++14
129
130    // arithmetic
131
132    time_point& operator+=(const duration& d); // constexpr in C++17
133    time_point& operator-=(const duration& d); // constexpr in C++17
134
135    // special values
136
137    static constexpr time_point min();  // noexcept in C++20
138    static constexpr time_point max();  // noexcept in C++20
139};
140
141} // chrono
142
143// common_type traits
144template <class Rep1, class Period1, class Rep2, class Period2>
145  struct common_type<chrono::duration<Rep1, Period1>, chrono::duration<Rep2, Period2>>;
146
147template <class Clock, class Duration1, class Duration2>
148  struct common_type<chrono::time_point<Clock, Duration1>, chrono::time_point<Clock, Duration2>>;
149
150namespace chrono {
151
152
153template<class T> struct is_clock;  // C++20
154template<class T> inline constexpr bool is_clock_v = is_clock<T>::value;   // C++20
155
156
157// duration arithmetic
158template <class Rep1, class Period1, class Rep2, class Period2>
159  constexpr
160  typename common_type<duration<Rep1, Period1>, duration<Rep2, Period2>>::type
161  operator+(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
162template <class Rep1, class Period1, class Rep2, class Period2>
163  constexpr
164  typename common_type<duration<Rep1, Period1>, duration<Rep2, Period2>>::type
165  operator-(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
166template <class Rep1, class Period, class Rep2>
167  constexpr
168  duration<typename common_type<Rep1, Rep2>::type, Period>
169  operator*(const duration<Rep1, Period>& d, const Rep2& s);
170template <class Rep1, class Period, class Rep2>
171  constexpr
172  duration<typename common_type<Rep1, Rep2>::type, Period>
173  operator*(const Rep1& s, const duration<Rep2, Period>& d);
174template <class Rep1, class Period, class Rep2>
175  constexpr
176  duration<typename common_type<Rep1, Rep2>::type, Period>
177  operator/(const duration<Rep1, Period>& d, const Rep2& s);
178template <class Rep1, class Period1, class Rep2, class Period2>
179  constexpr
180  typename common_type<Rep1, Rep2>::type
181  operator/(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
182
183// duration comparisons
184template <class Rep1, class Period1, class Rep2, class Period2>
185   constexpr
186   bool operator==(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
187template <class Rep1, class Period1, class Rep2, class Period2>
188   constexpr
189   bool operator!=(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
190template <class Rep1, class Period1, class Rep2, class Period2>
191   constexpr
192   bool operator< (const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
193template <class Rep1, class Period1, class Rep2, class Period2>
194   constexpr
195   bool operator<=(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
196template <class Rep1, class Period1, class Rep2, class Period2>
197   constexpr
198   bool operator> (const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
199template <class Rep1, class Period1, class Rep2, class Period2>
200   constexpr
201   bool operator>=(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
202
203// duration_cast
204template <class ToDuration, class Rep, class Period>
205  ToDuration duration_cast(const duration<Rep, Period>& d);
206
207template <class ToDuration, class Rep, class Period>
208    constexpr ToDuration floor(const duration<Rep, Period>& d);    // C++17
209template <class ToDuration, class Rep, class Period>
210    constexpr ToDuration ceil(const duration<Rep, Period>& d);     // C++17
211template <class ToDuration, class Rep, class Period>
212    constexpr ToDuration round(const duration<Rep, Period>& d);    // C++17
213
214// duration I/O is elsewhere
215
216// time_point arithmetic (all constexpr in C++14)
217template <class Clock, class Duration1, class Rep2, class Period2>
218  time_point<Clock, typename common_type<Duration1, duration<Rep2, Period2>>::type>
219  operator+(const time_point<Clock, Duration1>& lhs, const duration<Rep2, Period2>& rhs);
220template <class Rep1, class Period1, class Clock, class Duration2>
221  time_point<Clock, typename common_type<duration<Rep1, Period1>, Duration2>::type>
222  operator+(const duration<Rep1, Period1>& lhs, const time_point<Clock, Duration2>& rhs);
223template <class Clock, class Duration1, class Rep2, class Period2>
224  time_point<Clock, typename common_type<Duration1, duration<Rep2, Period2>>::type>
225  operator-(const time_point<Clock, Duration1>& lhs, const duration<Rep2, Period2>& rhs);
226template <class Clock, class Duration1, class Duration2>
227  typename common_type<Duration1, Duration2>::type
228  operator-(const time_point<Clock, Duration1>& lhs, const time_point<Clock, Duration2>& rhs);
229
230// time_point comparisons (all constexpr in C++14)
231template <class Clock, class Duration1, class Duration2>
232   bool operator==(const time_point<Clock, Duration1>& lhs, const time_point<Clock, Duration2>& rhs);
233template <class Clock, class Duration1, class Duration2>
234   bool operator!=(const time_point<Clock, Duration1>& lhs, const time_point<Clock, Duration2>& rhs);
235template <class Clock, class Duration1, class Duration2>
236   bool operator< (const time_point<Clock, Duration1>& lhs, const time_point<Clock, Duration2>& rhs);
237template <class Clock, class Duration1, class Duration2>
238   bool operator<=(const time_point<Clock, Duration1>& lhs, const time_point<Clock, Duration2>& rhs);
239template <class Clock, class Duration1, class Duration2>
240   bool operator> (const time_point<Clock, Duration1>& lhs, const time_point<Clock, Duration2>& rhs);
241template <class Clock, class Duration1, class Duration2>
242   bool operator>=(const time_point<Clock, Duration1>& lhs, const time_point<Clock, Duration2>& rhs);
243
244// time_point_cast (constexpr in C++14)
245
246template <class ToDuration, class Clock, class Duration>
247  time_point<Clock, ToDuration> time_point_cast(const time_point<Clock, Duration>& t);
248
249template <class ToDuration, class Clock, class Duration>
250    constexpr time_point<Clock, ToDuration>
251    floor(const time_point<Clock, Duration>& tp);                  // C++17
252
253template <class ToDuration, class Clock, class Duration>
254    constexpr time_point<Clock, ToDuration>
255    ceil(const time_point<Clock, Duration>& tp);                   // C++17
256
257template <class ToDuration, class Clock, class Duration>
258    constexpr time_point<Clock, ToDuration>
259    round(const time_point<Clock, Duration>& tp);                  // C++17
260
261template <class Rep, class Period>
262    constexpr duration<Rep, Period> abs(duration<Rep, Period> d);  // C++17
263
264// Clocks
265
266class system_clock
267{
268public:
269    typedef microseconds                     duration;
270    typedef duration::rep                    rep;
271    typedef duration::period                 period;
272    typedef chrono::time_point<system_clock> time_point;
273    static const bool is_steady =            false; // constexpr in C++14
274
275    static time_point now() noexcept;
276    static time_t     to_time_t  (const time_point& __t) noexcept;
277    static time_point from_time_t(time_t __t) noexcept;
278};
279
280template <class Duration>
281  using sys_time  = time_point<system_clock, Duration>; // C++20
282using sys_seconds = sys_time<seconds>;                  // C++20
283using sys_days    = sys_time<days>;                     // C++20
284
285class utc_clock;                                        // C++20
286
287template <class Duration>
288  using utc_time  = time_point<utc_clock, Duration>;    // C++20
289using utc_seconds = utc_time<seconds>;                  // C++20
290
291class tai_clock;                                        // C++20
292
293template <class Duration>
294  using tai_time  = time_point<tai_clock, Duration>;    // C++20
295using tai_seconds = tai_time<seconds>;                  // C++20
296
297class file_clock;                                       // C++20
298
299template<class Duration>
300  using file_time = time_point<file_clock, Duration>;   // C++20
301
302class steady_clock
303{
304public:
305    typedef nanoseconds                                   duration;
306    typedef duration::rep                                 rep;
307    typedef duration::period                              period;
308    typedef chrono::time_point<steady_clock, duration>    time_point;
309    static const bool is_steady =                         true; // constexpr in C++14
310
311    static time_point now() noexcept;
312};
313
314typedef steady_clock high_resolution_clock;
315
316// 25.7.8, local time           // C++20
317struct local_t {};
318template<class Duration>
319  using local_time  = time_point<local_t, Duration>;
320using local_seconds = local_time<seconds>;
321using local_days    = local_time<days>;
322
323// 25.7.9, time_point conversions template<class DestClock, class SourceClock>    // C++20
324struct clock_time_conversion;
325
326template<class DestClock, class SourceClock, class Duration>
327  auto clock_cast(const time_point<SourceClock, Duration>& t);
328
329// 25.8.2, class last_spec    // C++20
330struct last_spec;
331
332// 25.8.3, class day          // C++20
333
334class day;
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 bool operator>=(const day& x, const day& y) noexcept;
341constexpr day  operator+(const day&  x, const days& y) noexcept;
342constexpr day  operator+(const days& x, const day&  y) noexcept;
343constexpr day  operator-(const day&  x, const days& y) noexcept;
344constexpr days operator-(const day&  x, const day&  y) noexcept;
345
346// 25.8.4, class month    // C++20
347class month;
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 bool operator>=(const month& x, const month& y) noexcept;
354constexpr month  operator+(const month&  x, const months& y) noexcept;
355constexpr month  operator+(const months& x,  const month& y) noexcept;
356constexpr month  operator-(const month&  x, const months& y) noexcept;
357constexpr months operator-(const month&  x,  const month& y) noexcept;
358
359// 25.8.5, class year    // C++20
360class year;
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 bool operator>=(const year& x, const year& y) noexcept;
367constexpr year  operator+(const year&  x, const years& y) noexcept;
368constexpr year  operator+(const years& x, const year&  y) noexcept;
369constexpr year  operator-(const year&  x, const years& y) noexcept;
370constexpr years operator-(const year&  x, const year&  y) noexcept;
371
372// 25.8.6, class weekday    // C++20
373class weekday;
374
375constexpr bool operator==(const weekday& x, const weekday& y) noexcept;
376constexpr bool operator!=(const weekday& x, const weekday& y) noexcept;
377constexpr weekday operator+(const weekday& x, const days&    y) noexcept;
378constexpr weekday operator+(const days&    x, const weekday& y) noexcept;
379constexpr weekday operator-(const weekday& x, const days&    y) noexcept;
380constexpr days    operator-(const weekday& x, const weekday& y) noexcept;
381
382// 25.8.7, class weekday_indexed    // C++20
383
384class weekday_indexed;
385constexpr bool operator==(const weekday_indexed& x, const weekday_indexed& y) noexcept;
386constexpr bool operator!=(const weekday_indexed& x, const weekday_indexed& y) noexcept;
387
388// 25.8.8, class weekday_last    // C++20
389class weekday_last;
390
391constexpr bool operator==(const weekday_last& x, const weekday_last& y) noexcept;
392constexpr bool operator!=(const weekday_last& x, const weekday_last& y) noexcept;
393
394// 25.8.9, class month_day    // C++20
395class month_day;
396
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;
402constexpr bool operator>=(const month_day& x, const month_day& y) noexcept;
403
404
405// 25.8.10, class month_day_last    // C++20
406class month_day_last;
407
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;
413constexpr bool operator>=(const month_day_last& x, const month_day_last& y) noexcept;
414
415// 25.8.11, class month_weekday    // C++20
416class month_weekday;
417
418constexpr bool operator==(const month_weekday& x, const month_weekday& y) noexcept;
419constexpr bool operator!=(const month_weekday& x, const month_weekday& y) noexcept;
420
421// 25.8.12, class month_weekday_last    // C++20
422class month_weekday_last;
423
424constexpr bool operator==(const month_weekday_last& x, const month_weekday_last& y) noexcept;
425constexpr bool operator!=(const month_weekday_last& x, const month_weekday_last& y) noexcept;
426
427
428// 25.8.13, class year_month    // C++20
429class year_month;
430
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;
436constexpr bool operator>=(const year_month& x, const year_month& y) noexcept;
437
438constexpr year_month operator+(const year_month& ym, const months& dm) noexcept;
439constexpr year_month operator+(const months& dm, const year_month& ym) noexcept;
440constexpr year_month operator-(const year_month& ym, const months& dm) noexcept;
441constexpr months operator-(const year_month& x, const year_month& y) noexcept;
442constexpr year_month operator+(const year_month& ym, const years& dy) noexcept;
443constexpr year_month operator+(const years& dy, const year_month& ym) noexcept;
444constexpr year_month operator-(const year_month& ym, const years& dy) noexcept;
445
446// 25.8.14, class year_month_day class    // C++20
447year_month_day;
448
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;
454constexpr bool operator>=(const year_month_day& x, const year_month_day& y) noexcept;
455
456constexpr year_month_day operator+(const year_month_day& ymd, const months& dm) noexcept;
457constexpr year_month_day operator+(const months& dm, const year_month_day& ymd) noexcept;
458constexpr year_month_day operator+(const year_month_day& ymd, const years& dy) noexcept;
459constexpr year_month_day operator+(const years& dy, const year_month_day& ymd) noexcept;
460constexpr year_month_day operator-(const year_month_day& ymd, const months& dm) noexcept;
461constexpr year_month_day operator-(const year_month_day& ymd, const years& dy) noexcept;
462
463
464// 25.8.15, class year_month_day_last    // C++20
465class year_month_day_last;
466
467constexpr bool operator==(const year_month_day_last& x,
468                          const year_month_day_last& y) noexcept;
469constexpr bool operator!=(const year_month_day_last& x,
470                          const year_month_day_last& y) noexcept;
471constexpr bool operator< (const year_month_day_last& x,
472                          const year_month_day_last& y) noexcept;
473constexpr bool operator> (const year_month_day_last& x,
474                          const year_month_day_last& y) noexcept;
475constexpr bool operator<=(const year_month_day_last& x,
476                          const year_month_day_last& y) noexcept;
477constexpr bool operator>=(const year_month_day_last& x,
478                          const year_month_day_last& y) noexcept;
479
480constexpr year_month_day_last
481  operator+(const year_month_day_last& ymdl, const months& dm) noexcept;
482constexpr year_month_day_last
483  operator+(const months& dm, const year_month_day_last& ymdl) noexcept;
484constexpr year_month_day_last
485  operator+(const year_month_day_last& ymdl, const years& dy) noexcept;
486constexpr year_month_day_last
487  operator+(const years& dy, const year_month_day_last& ymdl) noexcept;
488constexpr year_month_day_last
489  operator-(const year_month_day_last& ymdl, const months& dm) noexcept;
490constexpr year_month_day_last
491  operator-(const year_month_day_last& ymdl, const years& dy) noexcept;
492
493// 25.8.16, class year_month_weekday    // C++20
494class year_month_weekday;
495
496constexpr bool operator==(const year_month_weekday& x,
497                          const year_month_weekday& y) noexcept;
498constexpr bool operator!=(const year_month_weekday& x,
499                          const year_month_weekday& y) noexcept;
500
501constexpr year_month_weekday
502  operator+(const year_month_weekday& ymwd, const months& dm) noexcept;
503constexpr year_month_weekday
504  operator+(const months& dm, const year_month_weekday& ymwd) noexcept;
505constexpr year_month_weekday
506  operator+(const year_month_weekday& ymwd, const years& dy) noexcept;
507constexpr year_month_weekday
508  operator+(const years& dy, const year_month_weekday& ymwd) noexcept;
509constexpr year_month_weekday
510  operator-(const year_month_weekday& ymwd, const months& dm) noexcept;
511constexpr year_month_weekday
512  operator-(const year_month_weekday& ymwd, const years& dy) noexcept;
513
514// 25.8.17, class year_month_weekday_last    // C++20
515class year_month_weekday_last;
516
517constexpr bool operator==(const year_month_weekday_last& x,
518                          const year_month_weekday_last& y) noexcept;
519constexpr bool operator!=(const year_month_weekday_last& x,
520                          const year_month_weekday_last& y) noexcept;
521constexpr year_month_weekday_last
522  operator+(const year_month_weekday_last& ymwdl, const months& dm) noexcept;
523constexpr year_month_weekday_last
524  operator+(const months& dm, const year_month_weekday_last& ymwdl) noexcept;
525constexpr year_month_weekday_last
526  operator+(const year_month_weekday_last& ymwdl, const years& dy) noexcept;
527constexpr year_month_weekday_last
528  operator+(const years& dy, const year_month_weekday_last& ymwdl) noexcept;
529constexpr year_month_weekday_last
530  operator-(const year_month_weekday_last& ymwdl, const months& dm) noexcept;
531constexpr year_month_weekday_last
532  operator-(const year_month_weekday_last& ymwdl, const years& dy) noexcept;
533
534// 25.8.18, civil calendar conventional syntax operators    // C++20
535constexpr year_month
536  operator/(const year& y, const month& m) noexcept;
537constexpr year_month
538  operator/(const year& y, int m) noexcept;
539constexpr month_day
540  operator/(const month& m, const day& d) noexcept;
541constexpr month_day
542  operator/(const month& m, int d) noexcept;
543constexpr month_day
544  operator/(int m, const day& d) noexcept;
545constexpr month_day
546  operator/(const day& d, const month& m) noexcept;
547constexpr month_day
548  operator/(const day& d, int m) noexcept;
549constexpr month_day_last
550  operator/(const month& m, last_spec) noexcept;
551constexpr month_day_last
552  operator/(int m, last_spec) noexcept;
553constexpr month_day_last
554  operator/(last_spec, const month& m) noexcept;
555constexpr month_day_last
556  operator/(last_spec, int m) noexcept;
557constexpr month_weekday
558  operator/(const month& m, const weekday_indexed& wdi) noexcept;
559constexpr month_weekday
560  operator/(int m, const weekday_indexed& wdi) noexcept;
561constexpr month_weekday
562  operator/(const weekday_indexed& wdi, const month& m) noexcept;
563constexpr month_weekday
564  operator/(const weekday_indexed& wdi, int m) noexcept;
565constexpr month_weekday_last
566  operator/(const month& m, const weekday_last& wdl) noexcept;
567constexpr month_weekday_last
568  operator/(int m, const weekday_last& wdl) noexcept;
569constexpr month_weekday_last
570  operator/(const weekday_last& wdl, const month& m) noexcept;
571constexpr month_weekday_last
572  operator/(const weekday_last& wdl, int m) noexcept;
573constexpr year_month_day
574  operator/(const year_month& ym, const day& d) noexcept;
575constexpr year_month_day
576  operator/(const year_month& ym, int d) noexcept;
577constexpr year_month_day
578  operator/(const year& y, const month_day& md) noexcept;
579constexpr year_month_day
580  operator/(int y, const month_day& md) noexcept;
581constexpr year_month_day
582  operator/(const month_day& md, const year& y) noexcept;
583constexpr year_month_day
584  operator/(const month_day& md, int y) noexcept;
585constexpr year_month_day_last
586  operator/(const year_month& ym, last_spec) noexcept;
587constexpr year_month_day_last
588  operator/(const year& y, const month_day_last& mdl) noexcept;
589constexpr year_month_day_last
590  operator/(int y, const month_day_last& mdl) noexcept;
591constexpr year_month_day_last
592  operator/(const month_day_last& mdl, const year& y) noexcept;
593constexpr year_month_day_last
594  operator/(const month_day_last& mdl, int y) noexcept;
595constexpr year_month_weekday
596  operator/(const year_month& ym, const weekday_indexed& wdi) noexcept;
597constexpr year_month_weekday
598  operator/(const year& y, const month_weekday& mwd) noexcept;
599constexpr year_month_weekday
600  operator/(int y, const month_weekday& mwd) noexcept;
601constexpr year_month_weekday
602  operator/(const month_weekday& mwd, const year& y) noexcept;
603constexpr year_month_weekday
604  operator/(const month_weekday& mwd, int y) noexcept;
605constexpr year_month_weekday_last
606  operator/(const year_month& ym, const weekday_last& wdl) noexcept;
607constexpr year_month_weekday_last
608  operator/(const year& y, const month_weekday_last& mwdl) noexcept;
609constexpr year_month_weekday_last
610  operator/(int y, const month_weekday_last& mwdl) noexcept;
611constexpr year_month_weekday_last
612  operator/(const month_weekday_last& mwdl, const year& y) noexcept;
613constexpr year_month_weekday_last
614  operator/(const month_weekday_last& mwdl, int y) noexcept;
615
616// 25.9, class template time_of_day    // C++20
617template<class Duration> class time_of_day;
618
619template<> class time_of_day<hours>;
620template<> class time_of_day<minutes>;
621template<> class time_of_day<seconds>;
622template<class Rep, class Period> class time_of_day<duration<Rep, Period>>;
623
624// 25.10.2, time zone database     // C++20
625struct tzdb;
626class tzdb_list;
627
628// 25.10.2.3, time zone database access    // C++20
629const tzdb& get_tzdb();
630tzdb_list& get_tzdb_list();
631const time_zone* locate_zone(string_view tz_name);
632const time_zone* current_zone();
633
634// 25.10.2.4, remote time zone database support    // C++20
635const tzdb& reload_tzdb();
636string remote_version();
637
638// 25.10.3, exception classes    // C++20
639class nonexistent_local_time;
640class ambiguous_local_time;
641
642// 25.10.4, information classes    // C++20
643struct sys_info;
644struct local_info;
645
646// 25.10.5, class time_zone    // C++20
647enum class choose {earliest, latest};
648class time_zone;
649bool operator==(const time_zone& x, const time_zone& y) noexcept;
650bool operator!=(const time_zone& x, const time_zone& y) noexcept;
651bool operator<(const time_zone& x, const time_zone& y) noexcept;
652bool operator>(const time_zone& x, const time_zone& y) noexcept;
653bool operator<=(const time_zone& x, const time_zone& y) noexcept;
654bool operator>=(const time_zone& x, const time_zone& y) noexcept;
655
656// 25.10.6, class template zoned_traits    // C++20
657template<class T> struct zoned_traits;
658
659// 25.10.7, class template zoned_time    // C++20
660template<class Duration, class TimeZonePtr = const time_zone*> class zoned_time;
661using zoned_seconds = zoned_time<seconds>;
662
663template<class Duration1, class Duration2, class TimeZonePtr>
664  bool operator==(const zoned_time<Duration1, TimeZonePtr>& x,
665                  const zoned_time<Duration2, TimeZonePtr>& y);
666template<class Duration1, class Duration2, class TimeZonePtr>
667  bool operator!=(const zoned_time<Duration1, TimeZonePtr>& x,
668                  const zoned_time<Duration2, TimeZonePtr>& y);
669
670// 25.10.8, leap second support    // C++20
671class leap;
672
673bool operator==(const leap& x, const leap& y);
674bool operator!=(const leap& x, const leap& y);
675bool operator< (const leap& x, const leap& y);
676bool operator> (const leap& x, const leap& y);
677bool operator<=(const leap& x, const leap& y);
678bool operator>=(const leap& x, const leap& y);
679template<class Duration>
680  bool operator==(const leap& x, const sys_time<Duration>& y);
681template<class Duration>
682  bool operator==(const sys_time<Duration>& x, const leap& y);
683template<class Duration>
684  bool operator!=(const leap& x, const sys_time<Duration>& y);
685template<class Duration>
686  bool operator!=(const sys_time<Duration>& x, const leap& y);
687template<class Duration>
688  bool operator< (const leap& x, const sys_time<Duration>& y);
689template<class Duration>
690  bool operator< (const sys_time<Duration>& x, const leap& y);
691template<class Duration>
692  bool operator> (const leap& x, const sys_time<Duration>& y);
693template<class Duration>
694  bool operator> (const sys_time<Duration>& x, const leap& y);
695template<class Duration>
696  bool operator<=(const leap& x, const sys_time<Duration>& y);
697template<class Duration>
698  bool operator<=(const sys_time<Duration>& x, const leap& y);
699template<class Duration>
700  bool operator>=(const leap& x, const sys_time<Duration>& y);
701template<class Duration>
702  bool operator>=(const sys_time<Duration>& x, const leap& y);
703
704// 25.10.9, class link    // C++20
705class link;
706bool operator==(const link& x, const link& y);
707bool operator!=(const link& x, const link& y);
708bool operator< (const link& x, const link& y);
709bool operator> (const link& x, const link& y);
710bool operator<=(const link& x, const link& y);
711bool operator>=(const link& x, const link& y);
712
713// 25.11, formatting    // C++20
714template<class charT, class Streamable>
715  basic_string<charT>
716    format(const charT* fmt, const Streamable& s);
717
718template<class charT, class Streamable>
719  basic_string<charT>
720    format(const locale& loc, const charT* fmt, const Streamable& s);
721
722template<class charT, class traits, class Alloc, class Streamable>
723  basic_string<charT, traits, Alloc>
724    format(const basic_string<charT, traits, Alloc>& fmt, const Streamable& s);
725
726template<class charT, class traits, class Alloc, class Streamable>
727  basic_string<charT, traits, Alloc>
728    format(const locale& loc, const basic_string<charT, traits, Alloc>& fmt,
729           const Streamable& s);
730
731// 25.12, parsing    // C++20
732template<class charT, class traits, class Alloc, class Parsable>
733unspecified
734    parse(const basic_string<charT, traits, Alloc>& format, Parsable& tp);
735
736template<class charT, class traits, class Alloc, class Parsable>
737unspecified
738    parse(const basic_string<charT, traits, Alloc>& format, Parsable& tp,
739          basic_string<charT, traits, Alloc>& abbrev);
740
741template<class charT, class traits, class Alloc, class Parsable>
742unspecified
743    parse(const basic_string<charT, traits, Alloc>& format, Parsable& tp,
744          minutes& offset);
745
746template<class charT, class traits, class Alloc, class Parsable>
747unspecified
748    parse(const basic_string<charT, traits, Alloc>& format, Parsable& tp,
749          basic_string<charT, traits, Alloc>& abbrev, minutes& offset);
750
751// calendrical constants
752inline constexpr last_spec                              last{};       // C++20
753inline constexpr chrono::weekday                        Sunday{0};    // C++20
754inline constexpr chrono::weekday                        Monday{1};    // C++20
755inline constexpr chrono::weekday                        Tuesday{2};   // C++20
756inline constexpr chrono::weekday                        Wednesday{3}; // C++20
757inline constexpr chrono::weekday                        Thursday{4};  // C++20
758inline constexpr chrono::weekday                        Friday{5};    // C++20
759inline constexpr chrono::weekday                        Saturday{6};  // C++20
760
761inline constexpr chrono::month                          January{1};   // C++20
762inline constexpr chrono::month                          February{2};  // C++20
763inline constexpr chrono::month                          March{3};     // C++20
764inline constexpr chrono::month                          April{4};     // C++20
765inline constexpr chrono::month                          May{5};       // C++20
766inline constexpr chrono::month                          June{6};      // C++20
767inline constexpr chrono::month                          July{7};      // C++20
768inline constexpr chrono::month                          August{8};    // C++20
769inline constexpr chrono::month                          September{9}; // C++20
770inline constexpr chrono::month                          October{10};  // C++20
771inline constexpr chrono::month                          November{11}; // C++20
772inline constexpr chrono::month                          December{12}; // C++20
773}  // chrono
774
775inline namespace literals {
776  inline namespace chrono_literals {
777constexpr chrono::hours                                 operator ""h(unsigned long long); // C++14
778constexpr chrono::duration<unspecified , ratio<3600,1>> operator ""h(long double); // C++14
779constexpr chrono::minutes                               operator ""min(unsigned long long); // C++14
780constexpr chrono::duration<unspecified , ratio<60,1>>   operator ""min(long double); // C++14
781constexpr chrono::seconds                               operator ""s(unsigned long long); // C++14
782constexpr chrono::duration<unspecified >                operator ""s(long double); // C++14
783constexpr chrono::milliseconds                          operator ""ms(unsigned long long); // C++14
784constexpr chrono::duration<unspecified , milli>         operator ""ms(long double); // C++14
785constexpr chrono::microseconds                          operator ""us(unsigned long long); // C++14
786constexpr chrono::duration<unspecified , micro>         operator ""us(long double); // C++14
787constexpr chrono::nanoseconds                           operator ""ns(unsigned long long); // C++14
788constexpr chrono::duration<unspecified , nano>          operator ""ns(long double); // C++14
789constexpr chrono::day                                   operator ""d(unsigned long long d) noexcept; // C++20
790constexpr chrono::year                                  operator ""y(unsigned long long y) noexcept; // C++20
791}  // chrono_literals
792}  // literals
793
794}  // std
795*/
796
797#include <__config>
798#include <ctime>
799#include <type_traits>
800#include <ratio>
801#include <limits>
802#include <version>
803
804#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
805#pragma GCC system_header
806#endif
807
808_LIBCPP_PUSH_MACROS
809#include <__undef_macros>
810
811#ifndef _LIBCPP_CXX03_LANG
812_LIBCPP_BEGIN_NAMESPACE_FILESYSTEM
813struct _FilesystemClock;
814_LIBCPP_END_NAMESPACE_FILESYSTEM
815#endif // !_LIBCPP_CXX03_LANG
816
817_LIBCPP_BEGIN_NAMESPACE_STD
818
819namespace chrono
820{
821
822template <class _Rep, class _Period = ratio<1> > class _LIBCPP_TEMPLATE_VIS duration;
823
824template <class _Tp>
825struct __is_duration : false_type {};
826
827template <class _Rep, class _Period>
828struct __is_duration<duration<_Rep, _Period> > : true_type  {};
829
830template <class _Rep, class _Period>
831struct __is_duration<const duration<_Rep, _Period> > : true_type  {};
832
833template <class _Rep, class _Period>
834struct __is_duration<volatile duration<_Rep, _Period> > : true_type  {};
835
836template <class _Rep, class _Period>
837struct __is_duration<const volatile duration<_Rep, _Period> > : true_type  {};
838
839} // chrono
840
841template <class _Rep1, class _Period1, class _Rep2, class _Period2>
842struct _LIBCPP_TEMPLATE_VIS common_type<chrono::duration<_Rep1, _Period1>,
843                                         chrono::duration<_Rep2, _Period2> >
844{
845    typedef chrono::duration<typename common_type<_Rep1, _Rep2>::type,
846                             typename __ratio_gcd<_Period1, _Period2>::type> type;
847};
848
849namespace chrono {
850
851// duration_cast
852
853template <class _FromDuration, class _ToDuration,
854          class _Period = typename ratio_divide<typename _FromDuration::period, typename _ToDuration::period>::type,
855          bool = _Period::num == 1,
856          bool = _Period::den == 1>
857struct __duration_cast;
858
859template <class _FromDuration, class _ToDuration, class _Period>
860struct __duration_cast<_FromDuration, _ToDuration, _Period, true, true>
861{
862    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
863    _ToDuration operator()(const _FromDuration& __fd) const
864    {
865        return _ToDuration(static_cast<typename _ToDuration::rep>(__fd.count()));
866    }
867};
868
869template <class _FromDuration, class _ToDuration, class _Period>
870struct __duration_cast<_FromDuration, _ToDuration, _Period, true, false>
871{
872    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
873    _ToDuration operator()(const _FromDuration& __fd) const
874    {
875        typedef typename common_type<typename _ToDuration::rep, typename _FromDuration::rep, intmax_t>::type _Ct;
876        return _ToDuration(static_cast<typename _ToDuration::rep>(
877                           static_cast<_Ct>(__fd.count()) / static_cast<_Ct>(_Period::den)));
878    }
879};
880
881template <class _FromDuration, class _ToDuration, class _Period>
882struct __duration_cast<_FromDuration, _ToDuration, _Period, false, true>
883{
884    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
885    _ToDuration operator()(const _FromDuration& __fd) const
886    {
887        typedef typename common_type<typename _ToDuration::rep, typename _FromDuration::rep, intmax_t>::type _Ct;
888        return _ToDuration(static_cast<typename _ToDuration::rep>(
889                           static_cast<_Ct>(__fd.count()) * static_cast<_Ct>(_Period::num)));
890    }
891};
892
893template <class _FromDuration, class _ToDuration, class _Period>
894struct __duration_cast<_FromDuration, _ToDuration, _Period, false, false>
895{
896    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
897    _ToDuration operator()(const _FromDuration& __fd) const
898    {
899        typedef typename common_type<typename _ToDuration::rep, typename _FromDuration::rep, intmax_t>::type _Ct;
900        return _ToDuration(static_cast<typename _ToDuration::rep>(
901                           static_cast<_Ct>(__fd.count()) * static_cast<_Ct>(_Period::num)
902                                                          / static_cast<_Ct>(_Period::den)));
903    }
904};
905
906template <class _ToDuration, class _Rep, class _Period>
907inline _LIBCPP_INLINE_VISIBILITY
908_LIBCPP_CONSTEXPR
909typename enable_if
910<
911    __is_duration<_ToDuration>::value,
912    _ToDuration
913>::type
914duration_cast(const duration<_Rep, _Period>& __fd)
915{
916    return __duration_cast<duration<_Rep, _Period>, _ToDuration>()(__fd);
917}
918
919template <class _Rep>
920struct _LIBCPP_TEMPLATE_VIS treat_as_floating_point : is_floating_point<_Rep> {};
921
922#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
923template <class _Rep>
924_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool treat_as_floating_point_v
925    = treat_as_floating_point<_Rep>::value;
926#endif
927
928template <class _Rep>
929struct _LIBCPP_TEMPLATE_VIS duration_values
930{
931public:
932    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR _Rep zero() _NOEXCEPT {return _Rep(0);}
933    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR _Rep max()  _NOEXCEPT {return numeric_limits<_Rep>::max();}
934    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR _Rep min()  _NOEXCEPT {return numeric_limits<_Rep>::lowest();}
935};
936
937#if _LIBCPP_STD_VER > 14
938template <class _ToDuration, class _Rep, class _Period>
939inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
940typename enable_if
941<
942    __is_duration<_ToDuration>::value,
943    _ToDuration
944>::type
945floor(const duration<_Rep, _Period>& __d)
946{
947    _ToDuration __t = duration_cast<_ToDuration>(__d);
948    if (__t > __d)
949        __t = __t - _ToDuration{1};
950    return __t;
951}
952
953template <class _ToDuration, class _Rep, class _Period>
954inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
955typename enable_if
956<
957    __is_duration<_ToDuration>::value,
958    _ToDuration
959>::type
960ceil(const duration<_Rep, _Period>& __d)
961{
962    _ToDuration __t = duration_cast<_ToDuration>(__d);
963    if (__t < __d)
964        __t = __t + _ToDuration{1};
965    return __t;
966}
967
968template <class _ToDuration, class _Rep, class _Period>
969inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
970typename enable_if
971<
972    __is_duration<_ToDuration>::value,
973    _ToDuration
974>::type
975round(const duration<_Rep, _Period>& __d)
976{
977    _ToDuration __lower = floor<_ToDuration>(__d);
978    _ToDuration __upper = __lower + _ToDuration{1};
979    auto __lowerDiff = __d - __lower;
980    auto __upperDiff = __upper - __d;
981    if (__lowerDiff < __upperDiff)
982        return __lower;
983    if (__lowerDiff > __upperDiff)
984        return __upper;
985    return __lower.count() & 1 ? __upper : __lower;
986}
987#endif
988
989// duration
990
991template <class _Rep, class _Period>
992class _LIBCPP_TEMPLATE_VIS duration
993{
994    static_assert(!__is_duration<_Rep>::value, "A duration representation can not be a duration");
995    static_assert(__is_ratio<_Period>::value, "Second template parameter of duration must be a std::ratio");
996    static_assert(_Period::num > 0, "duration period must be positive");
997
998    template <class _R1, class _R2>
999    struct __no_overflow
1000    {
1001    private:
1002        static const intmax_t __gcd_n1_n2 = __static_gcd<_R1::num, _R2::num>::value;
1003        static const intmax_t __gcd_d1_d2 = __static_gcd<_R1::den, _R2::den>::value;
1004        static const intmax_t __n1 = _R1::num / __gcd_n1_n2;
1005        static const intmax_t __d1 = _R1::den / __gcd_d1_d2;
1006        static const intmax_t __n2 = _R2::num / __gcd_n1_n2;
1007        static const intmax_t __d2 = _R2::den / __gcd_d1_d2;
1008        static const intmax_t max = -((intmax_t(1) << (sizeof(intmax_t) * CHAR_BIT - 1)) + 1);
1009
1010        template <intmax_t _Xp, intmax_t _Yp, bool __overflow>
1011        struct __mul    // __overflow == false
1012        {
1013            static const intmax_t value = _Xp * _Yp;
1014        };
1015
1016        template <intmax_t _Xp, intmax_t _Yp>
1017        struct __mul<_Xp, _Yp, true>
1018        {
1019            static const intmax_t value = 1;
1020        };
1021
1022    public:
1023        static const bool value = (__n1 <= max / __d2) && (__n2 <= max / __d1);
1024        typedef ratio<__mul<__n1, __d2, !value>::value,
1025                      __mul<__n2, __d1, !value>::value> type;
1026    };
1027
1028public:
1029    typedef _Rep rep;
1030    typedef typename _Period::type period;
1031private:
1032    rep __rep_;
1033public:
1034
1035    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1036#ifndef _LIBCPP_CXX03_LANG
1037        duration() = default;
1038#else
1039        duration() {}
1040#endif
1041
1042    template <class _Rep2>
1043        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1044        explicit duration(const _Rep2& __r,
1045            typename enable_if
1046            <
1047               is_convertible<_Rep2, rep>::value &&
1048               (treat_as_floating_point<rep>::value ||
1049               !treat_as_floating_point<_Rep2>::value)
1050            >::type* = 0)
1051                : __rep_(__r) {}
1052
1053    // conversions
1054    template <class _Rep2, class _Period2>
1055        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1056        duration(const duration<_Rep2, _Period2>& __d,
1057            typename enable_if
1058            <
1059                __no_overflow<_Period2, period>::value && (
1060                treat_as_floating_point<rep>::value ||
1061                (__no_overflow<_Period2, period>::type::den == 1 &&
1062                 !treat_as_floating_point<_Rep2>::value))
1063            >::type* = 0)
1064                : __rep_(_VSTD::chrono::duration_cast<duration>(__d).count()) {}
1065
1066    // observer
1067
1068    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR rep count() const {return __rep_;}
1069
1070    // arithmetic
1071
1072    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR typename common_type<duration>::type operator+() const {return typename common_type<duration>::type(*this);}
1073    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR typename common_type<duration>::type operator-() const {return typename common_type<duration>::type(-__rep_);}
1074    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration& operator++()      {++__rep_; return *this;}
1075    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration  operator++(int)   {return duration(__rep_++);}
1076    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration& operator--()      {--__rep_; return *this;}
1077    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration  operator--(int)   {return duration(__rep_--);}
1078
1079    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration& operator+=(const duration& __d) {__rep_ += __d.count(); return *this;}
1080    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration& operator-=(const duration& __d) {__rep_ -= __d.count(); return *this;}
1081
1082    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration& operator*=(const rep& rhs) {__rep_ *= rhs; return *this;}
1083    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration& operator/=(const rep& rhs) {__rep_ /= rhs; return *this;}
1084    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration& operator%=(const rep& rhs) {__rep_ %= rhs; return *this;}
1085    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration& operator%=(const duration& rhs) {__rep_ %= rhs.count(); return *this;}
1086
1087    // special values
1088
1089    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR duration zero() _NOEXCEPT {return duration(duration_values<rep>::zero());}
1090    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR duration min()  _NOEXCEPT {return duration(duration_values<rep>::min());}
1091    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR duration max()  _NOEXCEPT {return duration(duration_values<rep>::max());}
1092};
1093
1094typedef duration<long long,         nano> nanoseconds;
1095typedef duration<long long,        micro> microseconds;
1096typedef duration<long long,        milli> milliseconds;
1097typedef duration<long long              > seconds;
1098typedef duration<     long, ratio<  60> > minutes;
1099typedef duration<     long, ratio<3600> > hours;
1100#if _LIBCPP_STD_VER > 17
1101typedef duration<     int, ratio_multiply<ratio<24>, hours::period>>         days;
1102typedef duration<     int, ratio_multiply<ratio<7>,   days::period>>         weeks;
1103typedef duration<     int, ratio_multiply<ratio<146097, 400>, days::period>> years;
1104typedef duration<     int, ratio_divide<years::period, ratio<12>>>           months;
1105#endif
1106// Duration ==
1107
1108template <class _LhsDuration, class _RhsDuration>
1109struct __duration_eq
1110{
1111    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1112    bool operator()(const _LhsDuration& __lhs, const _RhsDuration& __rhs) const
1113        {
1114            typedef typename common_type<_LhsDuration, _RhsDuration>::type _Ct;
1115            return _Ct(__lhs).count() == _Ct(__rhs).count();
1116        }
1117};
1118
1119template <class _LhsDuration>
1120struct __duration_eq<_LhsDuration, _LhsDuration>
1121{
1122    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1123    bool operator()(const _LhsDuration& __lhs, const _LhsDuration& __rhs) const
1124        {return __lhs.count() == __rhs.count();}
1125};
1126
1127template <class _Rep1, class _Period1, class _Rep2, class _Period2>
1128inline _LIBCPP_INLINE_VISIBILITY
1129_LIBCPP_CONSTEXPR
1130bool
1131operator==(const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
1132{
1133    return __duration_eq<duration<_Rep1, _Period1>, duration<_Rep2, _Period2> >()(__lhs, __rhs);
1134}
1135
1136// Duration !=
1137
1138template <class _Rep1, class _Period1, class _Rep2, class _Period2>
1139inline _LIBCPP_INLINE_VISIBILITY
1140_LIBCPP_CONSTEXPR
1141bool
1142operator!=(const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
1143{
1144    return !(__lhs == __rhs);
1145}
1146
1147// Duration <
1148
1149template <class _LhsDuration, class _RhsDuration>
1150struct __duration_lt
1151{
1152    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1153    bool operator()(const _LhsDuration& __lhs, const _RhsDuration& __rhs) const
1154        {
1155            typedef typename common_type<_LhsDuration, _RhsDuration>::type _Ct;
1156            return _Ct(__lhs).count() < _Ct(__rhs).count();
1157        }
1158};
1159
1160template <class _LhsDuration>
1161struct __duration_lt<_LhsDuration, _LhsDuration>
1162{
1163    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1164    bool operator()(const _LhsDuration& __lhs, const _LhsDuration& __rhs) const
1165        {return __lhs.count() < __rhs.count();}
1166};
1167
1168template <class _Rep1, class _Period1, class _Rep2, class _Period2>
1169inline _LIBCPP_INLINE_VISIBILITY
1170_LIBCPP_CONSTEXPR
1171bool
1172operator< (const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
1173{
1174    return __duration_lt<duration<_Rep1, _Period1>, duration<_Rep2, _Period2> >()(__lhs, __rhs);
1175}
1176
1177// Duration >
1178
1179template <class _Rep1, class _Period1, class _Rep2, class _Period2>
1180inline _LIBCPP_INLINE_VISIBILITY
1181_LIBCPP_CONSTEXPR
1182bool
1183operator> (const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
1184{
1185    return __rhs < __lhs;
1186}
1187
1188// Duration <=
1189
1190template <class _Rep1, class _Period1, class _Rep2, class _Period2>
1191inline _LIBCPP_INLINE_VISIBILITY
1192_LIBCPP_CONSTEXPR
1193bool
1194operator<=(const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
1195{
1196    return !(__rhs < __lhs);
1197}
1198
1199// Duration >=
1200
1201template <class _Rep1, class _Period1, class _Rep2, class _Period2>
1202inline _LIBCPP_INLINE_VISIBILITY
1203_LIBCPP_CONSTEXPR
1204bool
1205operator>=(const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
1206{
1207    return !(__lhs < __rhs);
1208}
1209
1210// Duration +
1211
1212template <class _Rep1, class _Period1, class _Rep2, class _Period2>
1213inline _LIBCPP_INLINE_VISIBILITY
1214_LIBCPP_CONSTEXPR
1215typename common_type<duration<_Rep1, _Period1>, duration<_Rep2, _Period2> >::type
1216operator+(const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
1217{
1218    typedef typename common_type<duration<_Rep1, _Period1>, duration<_Rep2, _Period2> >::type _Cd;
1219    return _Cd(_Cd(__lhs).count() + _Cd(__rhs).count());
1220}
1221
1222// Duration -
1223
1224template <class _Rep1, class _Period1, class _Rep2, class _Period2>
1225inline _LIBCPP_INLINE_VISIBILITY
1226_LIBCPP_CONSTEXPR
1227typename common_type<duration<_Rep1, _Period1>, duration<_Rep2, _Period2> >::type
1228operator-(const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
1229{
1230    typedef typename common_type<duration<_Rep1, _Period1>, duration<_Rep2, _Period2> >::type _Cd;
1231    return _Cd(_Cd(__lhs).count() - _Cd(__rhs).count());
1232}
1233
1234// Duration *
1235
1236template <class _Rep1, class _Period, class _Rep2>
1237inline _LIBCPP_INLINE_VISIBILITY
1238_LIBCPP_CONSTEXPR
1239typename enable_if
1240<
1241    is_convertible<_Rep2, typename common_type<_Rep1, _Rep2>::type>::value,
1242    duration<typename common_type<_Rep1, _Rep2>::type, _Period>
1243>::type
1244operator*(const duration<_Rep1, _Period>& __d, const _Rep2& __s)
1245{
1246    typedef typename common_type<_Rep1, _Rep2>::type _Cr;
1247    typedef duration<_Cr, _Period> _Cd;
1248    return _Cd(_Cd(__d).count() * static_cast<_Cr>(__s));
1249}
1250
1251template <class _Rep1, class _Period, class _Rep2>
1252inline _LIBCPP_INLINE_VISIBILITY
1253_LIBCPP_CONSTEXPR
1254typename enable_if
1255<
1256    is_convertible<_Rep1, typename common_type<_Rep1, _Rep2>::type>::value,
1257    duration<typename common_type<_Rep1, _Rep2>::type, _Period>
1258>::type
1259operator*(const _Rep1& __s, const duration<_Rep2, _Period>& __d)
1260{
1261    return __d * __s;
1262}
1263
1264// Duration /
1265
1266template <class _Duration, class _Rep, bool = __is_duration<_Rep>::value>
1267struct __duration_divide_result
1268{
1269};
1270
1271template <class _Duration, class _Rep2,
1272    bool = is_convertible<_Rep2,
1273                          typename common_type<typename _Duration::rep, _Rep2>::type>::value>
1274struct __duration_divide_imp
1275{
1276};
1277
1278template <class _Rep1, class _Period, class _Rep2>
1279struct __duration_divide_imp<duration<_Rep1, _Period>, _Rep2, true>
1280{
1281    typedef duration<typename common_type<_Rep1, _Rep2>::type, _Period> type;
1282};
1283
1284template <class _Rep1, class _Period, class _Rep2>
1285struct __duration_divide_result<duration<_Rep1, _Period>, _Rep2, false>
1286    : __duration_divide_imp<duration<_Rep1, _Period>, _Rep2>
1287{
1288};
1289
1290template <class _Rep1, class _Period, class _Rep2>
1291inline _LIBCPP_INLINE_VISIBILITY
1292_LIBCPP_CONSTEXPR
1293typename __duration_divide_result<duration<_Rep1, _Period>, _Rep2>::type
1294operator/(const duration<_Rep1, _Period>& __d, const _Rep2& __s)
1295{
1296    typedef typename common_type<_Rep1, _Rep2>::type _Cr;
1297    typedef duration<_Cr, _Period> _Cd;
1298    return _Cd(_Cd(__d).count() / static_cast<_Cr>(__s));
1299}
1300
1301template <class _Rep1, class _Period1, class _Rep2, class _Period2>
1302inline _LIBCPP_INLINE_VISIBILITY
1303_LIBCPP_CONSTEXPR
1304typename common_type<_Rep1, _Rep2>::type
1305operator/(const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
1306{
1307    typedef typename common_type<duration<_Rep1, _Period1>, duration<_Rep2, _Period2> >::type _Ct;
1308    return _Ct(__lhs).count() / _Ct(__rhs).count();
1309}
1310
1311// Duration %
1312
1313template <class _Rep1, class _Period, class _Rep2>
1314inline _LIBCPP_INLINE_VISIBILITY
1315_LIBCPP_CONSTEXPR
1316typename __duration_divide_result<duration<_Rep1, _Period>, _Rep2>::type
1317operator%(const duration<_Rep1, _Period>& __d, const _Rep2& __s)
1318{
1319    typedef typename common_type<_Rep1, _Rep2>::type _Cr;
1320    typedef duration<_Cr, _Period> _Cd;
1321    return _Cd(_Cd(__d).count() % static_cast<_Cr>(__s));
1322}
1323
1324template <class _Rep1, class _Period1, class _Rep2, class _Period2>
1325inline _LIBCPP_INLINE_VISIBILITY
1326_LIBCPP_CONSTEXPR
1327typename common_type<duration<_Rep1, _Period1>, duration<_Rep2, _Period2> >::type
1328operator%(const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
1329{
1330    typedef typename common_type<_Rep1, _Rep2>::type _Cr;
1331    typedef typename common_type<duration<_Rep1, _Period1>, duration<_Rep2, _Period2> >::type _Cd;
1332    return _Cd(static_cast<_Cr>(_Cd(__lhs).count()) % static_cast<_Cr>(_Cd(__rhs).count()));
1333}
1334
1335//////////////////////////////////////////////////////////
1336///////////////////// time_point /////////////////////////
1337//////////////////////////////////////////////////////////
1338
1339template <class _Clock, class _Duration = typename _Clock::duration>
1340class _LIBCPP_TEMPLATE_VIS time_point
1341{
1342    static_assert(__is_duration<_Duration>::value,
1343                  "Second template parameter of time_point must be a std::chrono::duration");
1344public:
1345    typedef _Clock                    clock;
1346    typedef _Duration                 duration;
1347    typedef typename duration::rep    rep;
1348    typedef typename duration::period period;
1349private:
1350    duration __d_;
1351
1352public:
1353    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 time_point() : __d_(duration::zero()) {}
1354    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 explicit time_point(const duration& __d) : __d_(__d) {}
1355
1356    // conversions
1357    template <class _Duration2>
1358    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1359    time_point(const time_point<clock, _Duration2>& t,
1360        typename enable_if
1361        <
1362            is_convertible<_Duration2, duration>::value
1363        >::type* = 0)
1364            : __d_(t.time_since_epoch()) {}
1365
1366    // observer
1367
1368    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 duration time_since_epoch() const {return __d_;}
1369
1370    // arithmetic
1371
1372    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 time_point& operator+=(const duration& __d) {__d_ += __d; return *this;}
1373    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 time_point& operator-=(const duration& __d) {__d_ -= __d; return *this;}
1374
1375    // special values
1376
1377    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR time_point min() _NOEXCEPT {return time_point(duration::min());}
1378    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR time_point max() _NOEXCEPT {return time_point(duration::max());}
1379};
1380
1381} // chrono
1382
1383template <class _Clock, class _Duration1, class _Duration2>
1384struct _LIBCPP_TEMPLATE_VIS common_type<chrono::time_point<_Clock, _Duration1>,
1385                                         chrono::time_point<_Clock, _Duration2> >
1386{
1387    typedef chrono::time_point<_Clock, typename common_type<_Duration1, _Duration2>::type> type;
1388};
1389
1390namespace chrono {
1391
1392template <class _ToDuration, class _Clock, class _Duration>
1393inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1394time_point<_Clock, _ToDuration>
1395time_point_cast(const time_point<_Clock, _Duration>& __t)
1396{
1397    return time_point<_Clock, _ToDuration>(_VSTD::chrono::duration_cast<_ToDuration>(__t.time_since_epoch()));
1398}
1399
1400#if _LIBCPP_STD_VER > 14
1401template <class _ToDuration, class _Clock, class _Duration>
1402inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1403typename enable_if
1404<
1405    __is_duration<_ToDuration>::value,
1406    time_point<_Clock, _ToDuration>
1407>::type
1408floor(const time_point<_Clock, _Duration>& __t)
1409{
1410    return time_point<_Clock, _ToDuration>{floor<_ToDuration>(__t.time_since_epoch())};
1411}
1412
1413template <class _ToDuration, class _Clock, class _Duration>
1414inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1415typename enable_if
1416<
1417    __is_duration<_ToDuration>::value,
1418    time_point<_Clock, _ToDuration>
1419>::type
1420ceil(const time_point<_Clock, _Duration>& __t)
1421{
1422    return time_point<_Clock, _ToDuration>{ceil<_ToDuration>(__t.time_since_epoch())};
1423}
1424
1425template <class _ToDuration, class _Clock, class _Duration>
1426inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1427typename enable_if
1428<
1429    __is_duration<_ToDuration>::value,
1430    time_point<_Clock, _ToDuration>
1431>::type
1432round(const time_point<_Clock, _Duration>& __t)
1433{
1434    return time_point<_Clock, _ToDuration>{round<_ToDuration>(__t.time_since_epoch())};
1435}
1436
1437template <class _Rep, class _Period>
1438inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1439typename enable_if
1440<
1441    numeric_limits<_Rep>::is_signed,
1442    duration<_Rep, _Period>
1443>::type
1444abs(duration<_Rep, _Period> __d)
1445{
1446    return __d >= __d.zero() ? __d : -__d;
1447}
1448#endif
1449
1450// time_point ==
1451
1452template <class _Clock, class _Duration1, class _Duration2>
1453inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1454bool
1455operator==(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
1456{
1457    return __lhs.time_since_epoch() == __rhs.time_since_epoch();
1458}
1459
1460// time_point !=
1461
1462template <class _Clock, class _Duration1, class _Duration2>
1463inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1464bool
1465operator!=(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
1466{
1467    return !(__lhs == __rhs);
1468}
1469
1470// time_point <
1471
1472template <class _Clock, class _Duration1, class _Duration2>
1473inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1474bool
1475operator<(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
1476{
1477    return __lhs.time_since_epoch() < __rhs.time_since_epoch();
1478}
1479
1480// time_point >
1481
1482template <class _Clock, class _Duration1, class _Duration2>
1483inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1484bool
1485operator>(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
1486{
1487    return __rhs < __lhs;
1488}
1489
1490// time_point <=
1491
1492template <class _Clock, class _Duration1, class _Duration2>
1493inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1494bool
1495operator<=(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
1496{
1497    return !(__rhs < __lhs);
1498}
1499
1500// time_point >=
1501
1502template <class _Clock, class _Duration1, class _Duration2>
1503inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1504bool
1505operator>=(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
1506{
1507    return !(__lhs < __rhs);
1508}
1509
1510// time_point operator+(time_point x, duration y);
1511
1512template <class _Clock, class _Duration1, class _Rep2, class _Period2>
1513inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1514time_point<_Clock, typename common_type<_Duration1, duration<_Rep2, _Period2> >::type>
1515operator+(const time_point<_Clock, _Duration1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
1516{
1517    typedef time_point<_Clock, typename common_type<_Duration1, duration<_Rep2, _Period2> >::type> _Tr;
1518    return _Tr (__lhs.time_since_epoch() + __rhs);
1519}
1520
1521// time_point operator+(duration x, time_point y);
1522
1523template <class _Rep1, class _Period1, class _Clock, class _Duration2>
1524inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1525time_point<_Clock, typename common_type<duration<_Rep1, _Period1>, _Duration2>::type>
1526operator+(const duration<_Rep1, _Period1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
1527{
1528    return __rhs + __lhs;
1529}
1530
1531// time_point operator-(time_point x, duration y);
1532
1533template <class _Clock, class _Duration1, class _Rep2, class _Period2>
1534inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1535time_point<_Clock, typename common_type<_Duration1, duration<_Rep2, _Period2> >::type>
1536operator-(const time_point<_Clock, _Duration1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
1537{
1538    typedef time_point<_Clock, typename common_type<_Duration1, duration<_Rep2, _Period2> >::type> _Ret;
1539    return _Ret(__lhs.time_since_epoch() -__rhs);
1540}
1541
1542// duration operator-(time_point x, time_point y);
1543
1544template <class _Clock, class _Duration1, class _Duration2>
1545inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1546typename common_type<_Duration1, _Duration2>::type
1547operator-(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
1548{
1549    return __lhs.time_since_epoch() - __rhs.time_since_epoch();
1550}
1551
1552//////////////////////////////////////////////////////////
1553/////////////////////// clocks ///////////////////////////
1554//////////////////////////////////////////////////////////
1555
1556class _LIBCPP_TYPE_VIS system_clock
1557{
1558public:
1559    typedef microseconds                     duration;
1560    typedef duration::rep                    rep;
1561    typedef duration::period                 period;
1562    typedef chrono::time_point<system_clock> time_point;
1563    static _LIBCPP_CONSTEXPR_AFTER_CXX11 const bool is_steady = false;
1564
1565    static time_point now() _NOEXCEPT;
1566    static time_t     to_time_t  (const time_point& __t) _NOEXCEPT;
1567    static time_point from_time_t(time_t __t) _NOEXCEPT;
1568};
1569
1570#ifndef _LIBCPP_HAS_NO_MONOTONIC_CLOCK
1571class _LIBCPP_TYPE_VIS steady_clock
1572{
1573public:
1574    typedef nanoseconds                                   duration;
1575    typedef duration::rep                                 rep;
1576    typedef duration::period                              period;
1577    typedef chrono::time_point<steady_clock, duration>    time_point;
1578    static _LIBCPP_CONSTEXPR_AFTER_CXX11 const bool is_steady = true;
1579
1580    static time_point now() _NOEXCEPT;
1581};
1582
1583typedef steady_clock high_resolution_clock;
1584#else
1585typedef system_clock high_resolution_clock;
1586#endif
1587
1588#if _LIBCPP_STD_VER > 17
1589// [time.clock.file], type file_clock
1590using file_clock = _VSTD_FS::_FilesystemClock;
1591
1592template<class _Duration>
1593using file_time = time_point<file_clock, _Duration>;
1594
1595
1596template <class _Duration>
1597using sys_time    = time_point<system_clock, _Duration>;
1598using sys_seconds = sys_time<seconds>;
1599using sys_days    = sys_time<days>;
1600
1601struct local_t {};
1602template<class Duration>
1603using local_time  = time_point<local_t, Duration>;
1604using local_seconds = local_time<seconds>;
1605using local_days    = local_time<days>;
1606
1607
1608struct _LIBCPP_TYPE_VIS last_spec { explicit last_spec() = default; };
1609
1610class _LIBCPP_TYPE_VIS day {
1611private:
1612    unsigned char __d;
1613public:
1614    day() = default;
1615    explicit inline constexpr day(unsigned __val) noexcept : __d(static_cast<unsigned char>(__val)) {}
1616    inline constexpr day& operator++()    noexcept { ++__d; return *this; }
1617    inline constexpr day  operator++(int) noexcept { day __tmp = *this; ++(*this); return __tmp; }
1618    inline constexpr day& operator--()    noexcept { --__d; return *this; }
1619    inline constexpr day  operator--(int) noexcept { day __tmp = *this; --(*this); return __tmp; }
1620           constexpr day& operator+=(const days& __dd) noexcept;
1621           constexpr day& operator-=(const days& __dd) noexcept;
1622    explicit inline constexpr operator unsigned() const noexcept { return __d; }
1623    inline constexpr bool ok() const noexcept { return __d >= 1 && __d <= 31; }
1624  };
1625
1626
1627inline constexpr
1628bool operator==(const day& __lhs, const day& __rhs) noexcept
1629{ return static_cast<unsigned>(__lhs) == static_cast<unsigned>(__rhs); }
1630
1631inline constexpr
1632bool operator!=(const day& __lhs, const day& __rhs) noexcept
1633{ return !(__lhs == __rhs); }
1634
1635inline constexpr
1636bool operator< (const day& __lhs, const day& __rhs) noexcept
1637{ return static_cast<unsigned>(__lhs) <  static_cast<unsigned>(__rhs); }
1638
1639inline constexpr
1640bool operator> (const day& __lhs, const day& __rhs) noexcept
1641{ return __rhs < __lhs; }
1642
1643inline constexpr
1644bool operator<=(const day& __lhs, const day& __rhs) noexcept
1645{ return !(__rhs < __lhs);}
1646
1647inline constexpr
1648bool operator>=(const day& __lhs, const day& __rhs) noexcept
1649{ return !(__lhs < __rhs); }
1650
1651inline constexpr
1652day operator+ (const day& __lhs, const days& __rhs) noexcept
1653{ return day(static_cast<unsigned>(__lhs) + __rhs.count()); }
1654
1655inline constexpr
1656day operator+ (const days& __lhs, const day& __rhs) noexcept
1657{ return __rhs + __lhs; }
1658
1659inline constexpr
1660day operator- (const day& __lhs, const days& __rhs) noexcept
1661{ return __lhs + -__rhs; }
1662
1663inline constexpr
1664days operator-(const day& __lhs, const day& __rhs) noexcept
1665{ return days(static_cast<int>(static_cast<unsigned>(__lhs)) -
1666              static_cast<int>(static_cast<unsigned>(__rhs))); }
1667
1668inline constexpr day& day::operator+=(const days& __dd) noexcept
1669{ *this = *this + __dd; return *this; }
1670
1671inline constexpr day& day::operator-=(const days& __dd) noexcept
1672{ *this = *this - __dd; return *this; }
1673
1674
1675class _LIBCPP_TYPE_VIS month {
1676private:
1677    unsigned char __m;
1678public:
1679    month() = default;
1680    explicit inline constexpr month(unsigned __val) noexcept : __m(static_cast<unsigned char>(__val)) {}
1681    inline constexpr month& operator++()    noexcept { ++__m; return *this; }
1682    inline constexpr month  operator++(int) noexcept { month __tmp = *this; ++(*this); return __tmp; }
1683    inline constexpr month& operator--()    noexcept { --__m; return *this; }
1684    inline constexpr month  operator--(int) noexcept { month __tmp = *this; --(*this); return __tmp; }
1685           constexpr month& operator+=(const months& __m1) noexcept;
1686           constexpr month& operator-=(const months& __m1) noexcept;
1687    explicit inline constexpr operator unsigned() const noexcept { return __m; }
1688    inline constexpr bool ok() const noexcept { return __m >= 1 && __m <= 12; }
1689};
1690
1691
1692inline constexpr
1693bool operator==(const month& __lhs, const month& __rhs) noexcept
1694{ return static_cast<unsigned>(__lhs) == static_cast<unsigned>(__rhs); }
1695
1696inline constexpr
1697bool operator!=(const month& __lhs, const month& __rhs) noexcept
1698{ return !(__lhs == __rhs); }
1699
1700inline constexpr
1701bool operator< (const month& __lhs, const month& __rhs) noexcept
1702{ return static_cast<unsigned>(__lhs)  < static_cast<unsigned>(__rhs); }
1703
1704inline constexpr
1705bool operator> (const month& __lhs, const month& __rhs) noexcept
1706{ return __rhs < __lhs; }
1707
1708inline constexpr
1709bool operator<=(const month& __lhs, const month& __rhs) noexcept
1710{ return !(__rhs < __lhs); }
1711
1712inline constexpr
1713bool operator>=(const month& __lhs, const month& __rhs) noexcept
1714{ return !(__lhs < __rhs); }
1715
1716inline constexpr
1717month operator+ (const month& __lhs, const months& __rhs) noexcept
1718{
1719    auto const __mu = static_cast<long long>(static_cast<unsigned>(__lhs)) + (__rhs.count() - 1);
1720    auto const __yr = (__mu >= 0 ? __mu : __mu - 11) / 12;
1721    return month{static_cast<unsigned>(__mu - __yr * 12 + 1)};
1722}
1723
1724inline constexpr
1725month operator+ (const months& __lhs, const month& __rhs) noexcept
1726{ return __rhs + __lhs; }
1727
1728inline constexpr
1729month operator- (const month& __lhs, const months& __rhs) noexcept
1730{ return __lhs + -__rhs; }
1731
1732inline constexpr
1733months operator-(const month& __lhs, const month& __rhs) noexcept
1734{
1735    auto const __dm = static_cast<unsigned>(__lhs) - static_cast<unsigned>(__rhs);
1736    return months(__dm <= 11 ? __dm : __dm + 12);
1737}
1738
1739inline constexpr month& month::operator+=(const months& __dm) noexcept
1740{ *this = *this + __dm; return *this; }
1741
1742inline constexpr month& month::operator-=(const months& __dm) noexcept
1743{ *this = *this - __dm; return *this; }
1744
1745
1746class _LIBCPP_TYPE_VIS year {
1747private:
1748    short __y;
1749public:
1750    year() = default;
1751    explicit inline constexpr year(int __val) noexcept : __y(static_cast<short>(__val)) {}
1752
1753    inline constexpr year& operator++()    noexcept { ++__y; return *this; };
1754    inline constexpr year  operator++(int) noexcept { year __tmp = *this; ++(*this); return __tmp; };
1755    inline constexpr year& operator--()    noexcept { --__y; return *this; };
1756    inline constexpr year  operator--(int) noexcept { year __tmp = *this; --(*this); return __tmp; };
1757           constexpr year& operator+=(const years& __dy) noexcept;
1758           constexpr year& operator-=(const years& __dy) noexcept;
1759    inline constexpr year operator+() const noexcept { return *this; }
1760    inline constexpr year operator-() const noexcept { return year{-__y}; };
1761
1762    inline constexpr bool is_leap() const noexcept { return __y % 4 == 0 && (__y % 100 != 0 || __y % 400 == 0); }
1763    explicit inline constexpr operator int() const noexcept { return __y; }
1764           constexpr bool ok() const noexcept;
1765    static inline constexpr year min() noexcept { return year{-32767}; }
1766    static inline constexpr year max() noexcept { return year{ 32767}; }
1767};
1768
1769
1770inline constexpr
1771bool operator==(const year& __lhs, const year& __rhs) noexcept
1772{ return static_cast<int>(__lhs) == static_cast<int>(__rhs); }
1773
1774inline constexpr
1775bool operator!=(const year& __lhs, const year& __rhs) noexcept
1776{ return !(__lhs == __rhs); }
1777
1778inline constexpr
1779bool operator< (const year& __lhs, const year& __rhs) noexcept
1780{ return static_cast<int>(__lhs)  < static_cast<int>(__rhs); }
1781
1782inline constexpr
1783bool operator> (const year& __lhs, const year& __rhs) noexcept
1784{ return __rhs < __lhs; }
1785
1786inline constexpr
1787bool operator<=(const year& __lhs, const year& __rhs) noexcept
1788{ return !(__rhs < __lhs); }
1789
1790inline constexpr
1791bool operator>=(const year& __lhs, const year& __rhs) noexcept
1792{ return !(__lhs < __rhs); }
1793
1794inline constexpr
1795year operator+ (const year& __lhs, const years& __rhs) noexcept
1796{ return year(static_cast<int>(__lhs) + __rhs.count()); }
1797
1798inline constexpr
1799year operator+ (const years& __lhs, const year& __rhs) noexcept
1800{ return __rhs + __lhs; }
1801
1802inline constexpr
1803year operator- (const year& __lhs, const years& __rhs) noexcept
1804{ return __lhs + -__rhs; }
1805
1806inline constexpr
1807years operator-(const year& __lhs, const year& __rhs) noexcept
1808{ return years{static_cast<int>(__lhs) - static_cast<int>(__rhs)}; }
1809
1810
1811inline constexpr year& year::operator+=(const years& __dy) noexcept
1812{ *this = *this + __dy; return *this; }
1813
1814inline constexpr year& year::operator-=(const years& __dy) noexcept
1815{ *this = *this - __dy; return *this; }
1816
1817inline constexpr bool year::ok() const noexcept
1818{ return static_cast<int>(min()) <= __y && __y <= static_cast<int>(max()); }
1819
1820class _LIBCPP_TYPE_VIS weekday_indexed;
1821class _LIBCPP_TYPE_VIS weekday_last;
1822
1823class _LIBCPP_TYPE_VIS weekday {
1824private:
1825    unsigned char __wd;
1826public:
1827  weekday() = default;
1828  inline explicit constexpr weekday(unsigned __val) noexcept : __wd(static_cast<unsigned char>(__val)) {}
1829  inline constexpr          weekday(const sys_days& __sysd) noexcept
1830          : __wd(__weekday_from_days(__sysd.time_since_epoch().count())) {}
1831  inline explicit constexpr weekday(const local_days& __locd) noexcept
1832          : __wd(__weekday_from_days(__locd.time_since_epoch().count())) {}
1833
1834  inline constexpr weekday& operator++()    noexcept { __wd = (__wd == 6 ? 0 : __wd + 1); return *this; }
1835  inline constexpr weekday  operator++(int) noexcept { weekday __tmp = *this; ++(*this); return __tmp; }
1836  inline constexpr weekday& operator--()    noexcept { __wd = (__wd == 0 ? 6 : __wd - 1); return *this; }
1837  inline constexpr weekday  operator--(int) noexcept { weekday __tmp = *this; --(*this); return __tmp; }
1838         constexpr weekday& operator+=(const days& __dd) noexcept;
1839         constexpr weekday& operator-=(const days& __dd) noexcept;
1840  inline explicit constexpr operator unsigned() const noexcept { return __wd; }
1841  inline constexpr bool ok() const noexcept { return __wd <= 6; }
1842         constexpr weekday_indexed operator[](unsigned __index) const noexcept;
1843         constexpr weekday_last    operator[](last_spec) const noexcept;
1844
1845  static constexpr unsigned char __weekday_from_days(int __days) noexcept;
1846};
1847
1848
1849// https://howardhinnant.github.io/date_algorithms.html#weekday_from_days
1850inline constexpr
1851unsigned char weekday::__weekday_from_days(int __days) noexcept
1852{
1853    return static_cast<unsigned char>(
1854              static_cast<unsigned>(__days >= -4 ? (__days+4) % 7 : (__days+5) % 7 + 6)
1855           );
1856}
1857
1858inline constexpr
1859bool operator==(const weekday& __lhs, const weekday& __rhs) noexcept
1860{ return static_cast<unsigned>(__lhs) == static_cast<unsigned>(__rhs); }
1861
1862inline constexpr
1863bool operator!=(const weekday& __lhs, const weekday& __rhs) noexcept
1864{ return !(__lhs == __rhs); }
1865
1866inline constexpr
1867bool operator< (const weekday& __lhs, const weekday& __rhs) noexcept
1868{ return static_cast<unsigned>(__lhs) <  static_cast<unsigned>(__rhs); }
1869
1870inline constexpr
1871bool operator> (const weekday& __lhs, const weekday& __rhs) noexcept
1872{ return __rhs < __lhs; }
1873
1874inline constexpr
1875bool operator<=(const weekday& __lhs, const weekday& __rhs) noexcept
1876{ return !(__rhs < __lhs);}
1877
1878inline constexpr
1879bool operator>=(const weekday& __lhs, const weekday& __rhs) noexcept
1880{ return !(__lhs < __rhs); }
1881
1882constexpr weekday operator+(const weekday& __lhs, const days& __rhs) noexcept
1883{
1884    auto const __mu = static_cast<long long>(static_cast<unsigned>(__lhs)) + __rhs.count();
1885    auto const __yr = (__mu >= 0 ? __mu : __mu - 6) / 7;
1886    return weekday{static_cast<unsigned>(__mu - __yr * 7)};
1887}
1888
1889constexpr weekday operator+(const days& __lhs, const weekday& __rhs) noexcept
1890{ return __rhs + __lhs; }
1891
1892constexpr weekday operator-(const weekday& __lhs, const days& __rhs) noexcept
1893{ return __lhs + -__rhs; }
1894
1895constexpr days operator-(const weekday& __lhs, const weekday& __rhs) noexcept
1896{
1897    const int __wdu = static_cast<unsigned>(__lhs) - static_cast<unsigned>(__rhs);
1898    const int __wk = (__wdu >= 0 ? __wdu : __wdu-6) / 7;
1899    return days{__wdu - __wk * 7};
1900}
1901
1902inline constexpr weekday& weekday::operator+=(const days& __dd) noexcept
1903{ *this = *this + __dd; return *this; }
1904
1905inline constexpr weekday& weekday::operator-=(const days& __dd) noexcept
1906{ *this = *this - __dd; return *this; }
1907
1908
1909class _LIBCPP_TYPE_VIS weekday_indexed {
1910private:
1911    _VSTD::chrono::weekday __wd;
1912    unsigned char          __idx;
1913public:
1914    weekday_indexed() = default;
1915    inline constexpr weekday_indexed(const _VSTD::chrono::weekday& __wdval, unsigned __idxval) noexcept
1916        : __wd{__wdval}, __idx(__idxval) {}
1917    inline constexpr _VSTD::chrono::weekday weekday() const noexcept { return __wd; }
1918    inline constexpr unsigned                 index() const noexcept { return __idx; }
1919    inline constexpr bool ok() const noexcept { return __wd.ok() && __idx >= 1 && __idx <= 5; }
1920};
1921
1922inline constexpr
1923bool operator==(const weekday_indexed& __lhs, const weekday_indexed& __rhs) noexcept
1924{ return __lhs.weekday() == __rhs.weekday() && __lhs.index() == __rhs.index(); }
1925
1926inline constexpr
1927bool operator!=(const weekday_indexed& __lhs, const weekday_indexed& __rhs) noexcept
1928{ return !(__lhs == __rhs); }
1929
1930
1931class _LIBCPP_TYPE_VIS weekday_last {
1932private:
1933    _VSTD::chrono::weekday __wd;
1934public:
1935    explicit constexpr weekday_last(const _VSTD::chrono::weekday& __val) noexcept
1936        : __wd{__val} {}
1937    constexpr _VSTD::chrono::weekday weekday() const noexcept { return __wd; }
1938    constexpr bool ok() const noexcept { return __wd.ok(); }
1939};
1940
1941inline constexpr
1942bool operator==(const weekday_last& __lhs, const weekday_last& __rhs) noexcept
1943{ return __lhs.weekday() == __rhs.weekday(); }
1944
1945inline constexpr
1946bool operator!=(const weekday_last& __lhs, const weekday_last& __rhs) noexcept
1947{ return !(__lhs == __rhs); }
1948
1949inline constexpr
1950weekday_indexed weekday::operator[](unsigned __index) const noexcept { return weekday_indexed{*this, __index}; }
1951
1952inline constexpr
1953weekday_last    weekday::operator[](last_spec) const noexcept { return weekday_last{*this}; }
1954
1955
1956inline constexpr last_spec last{};
1957inline constexpr weekday   Sunday{0};
1958inline constexpr weekday   Monday{1};
1959inline constexpr weekday   Tuesday{2};
1960inline constexpr weekday   Wednesday{3};
1961inline constexpr weekday   Thursday{4};
1962inline constexpr weekday   Friday{5};
1963inline constexpr weekday   Saturday{6};
1964
1965inline constexpr month January{1};
1966inline constexpr month February{2};
1967inline constexpr month March{3};
1968inline constexpr month April{4};
1969inline constexpr month May{5};
1970inline constexpr month June{6};
1971inline constexpr month July{7};
1972inline constexpr month August{8};
1973inline constexpr month September{9};
1974inline constexpr month October{10};
1975inline constexpr month November{11};
1976inline constexpr month December{12};
1977
1978
1979class _LIBCPP_TYPE_VIS month_day {
1980private:
1981   chrono::month __m;
1982   chrono::day   __d;
1983public:
1984    month_day() = default;
1985    constexpr month_day(const chrono::month& __mval, const chrono::day& __dval) noexcept
1986        : __m{__mval}, __d{__dval} {}
1987    inline constexpr chrono::month month() const noexcept { return __m; }
1988    inline constexpr chrono::day   day()   const noexcept { return __d; }
1989    constexpr bool ok() const noexcept;
1990};
1991
1992inline constexpr
1993bool month_day::ok() const noexcept
1994{
1995    if (!__m.ok()) return false;
1996    const unsigned __dval = static_cast<unsigned>(__d);
1997    if (__dval < 1 || __dval > 31) return false;
1998    if (__dval <= 29) return true;
1999//  Now we've got either 30 or 31
2000    const unsigned __mval = static_cast<unsigned>(__m);
2001    if (__mval == 2) return false;
2002    if (__mval == 4 || __mval == 6 || __mval == 9 || __mval == 11)
2003        return __dval == 30;
2004    return true;
2005}
2006
2007inline constexpr
2008bool operator==(const month_day& __lhs, const month_day& __rhs) noexcept
2009{ return __lhs.month() == __rhs.month() && __lhs.day() == __rhs.day(); }
2010
2011inline constexpr
2012bool operator!=(const month_day& __lhs, const month_day& __rhs) noexcept
2013{ return !(__lhs == __rhs); }
2014
2015inline constexpr
2016month_day operator/(const month& __lhs, const day& __rhs) noexcept
2017{ return month_day{__lhs, __rhs}; }
2018
2019constexpr
2020month_day operator/(const day& __lhs, const month& __rhs) noexcept
2021{ return __rhs / __lhs; }
2022
2023inline constexpr
2024month_day operator/(const month& __lhs, int __rhs) noexcept
2025{ return __lhs / day(__rhs); }
2026
2027constexpr
2028month_day operator/(int __lhs, const day& __rhs) noexcept
2029{ return month(__lhs) / __rhs; }
2030
2031constexpr
2032month_day operator/(const day& __lhs, int __rhs) noexcept
2033{ return month(__rhs) / __lhs; }
2034
2035
2036inline constexpr
2037bool operator< (const month_day& __lhs, const month_day& __rhs) noexcept
2038{ return __lhs.month() != __rhs.month() ? __lhs.month() < __rhs.month() : __lhs.day() < __rhs.day(); }
2039
2040inline constexpr
2041bool operator> (const month_day& __lhs, const month_day& __rhs) noexcept
2042{ return __rhs < __lhs; }
2043
2044inline constexpr
2045bool operator<=(const month_day& __lhs, const month_day& __rhs) noexcept
2046{ return !(__rhs < __lhs);}
2047
2048inline constexpr
2049bool operator>=(const month_day& __lhs, const month_day& __rhs) noexcept
2050{ return !(__lhs < __rhs); }
2051
2052
2053
2054class _LIBCPP_TYPE_VIS month_day_last {
2055private:
2056    chrono::month __m;
2057public:
2058    explicit constexpr month_day_last(const chrono::month& __val) noexcept
2059        : __m{__val} {}
2060    inline constexpr chrono::month month() const noexcept { return __m; }
2061    inline constexpr bool ok() const noexcept { return __m.ok(); }
2062};
2063
2064inline constexpr
2065bool operator==(const month_day_last& __lhs, const month_day_last& __rhs) noexcept
2066{ return __lhs.month() == __rhs.month(); }
2067
2068inline constexpr
2069bool operator!=(const month_day_last& __lhs, const month_day_last& __rhs) noexcept
2070{ return !(__lhs == __rhs); }
2071
2072inline constexpr
2073bool operator< (const month_day_last& __lhs, const month_day_last& __rhs) noexcept
2074{ return __lhs.month() < __rhs.month(); }
2075
2076inline constexpr
2077bool operator> (const month_day_last& __lhs, const month_day_last& __rhs) noexcept
2078{ return __rhs < __lhs; }
2079
2080inline constexpr
2081bool operator<=(const month_day_last& __lhs, const month_day_last& __rhs) noexcept
2082{ return !(__rhs < __lhs);}
2083
2084inline constexpr
2085bool operator>=(const month_day_last& __lhs, const month_day_last& __rhs) noexcept
2086{ return !(__lhs < __rhs); }
2087
2088inline constexpr
2089month_day_last operator/(const month& __lhs, last_spec) noexcept
2090{ return month_day_last{__lhs}; }
2091
2092inline constexpr
2093month_day_last operator/(last_spec, const month& __rhs) noexcept
2094{ return month_day_last{__rhs}; }
2095
2096inline constexpr
2097month_day_last operator/(int __lhs, last_spec) noexcept
2098{ return month_day_last{month(__lhs)}; }
2099
2100inline constexpr
2101month_day_last operator/(last_spec, int __rhs) noexcept
2102{ return month_day_last{month(__rhs)}; }
2103
2104
2105class _LIBCPP_TYPE_VIS month_weekday {
2106private:
2107    chrono::month __m;
2108    chrono::weekday_indexed __wdi;
2109public:
2110    month_weekday() = default;
2111    constexpr month_weekday(const chrono::month& __mval, const chrono::weekday_indexed& __wdival) noexcept
2112        : __m{__mval}, __wdi{__wdival} {}
2113    inline constexpr chrono::month                     month() const noexcept { return __m; }
2114    inline constexpr chrono::weekday_indexed weekday_indexed() const noexcept { return __wdi; }
2115    inline constexpr bool                                 ok() const noexcept { return __m.ok() && __wdi.ok(); }
2116};
2117
2118inline constexpr
2119bool operator==(const month_weekday& __lhs, const month_weekday& __rhs) noexcept
2120{ return __lhs.month() == __rhs.month() && __lhs.weekday_indexed() == __rhs.weekday_indexed(); }
2121
2122inline constexpr
2123bool operator!=(const month_weekday& __lhs, const month_weekday& __rhs) noexcept
2124{ return !(__lhs == __rhs); }
2125
2126inline constexpr
2127month_weekday operator/(const month& __lhs, const weekday_indexed& __rhs) noexcept
2128{ return month_weekday{__lhs, __rhs}; }
2129
2130inline constexpr
2131month_weekday operator/(int __lhs, const weekday_indexed& __rhs) noexcept
2132{ return month_weekday{month(__lhs), __rhs}; }
2133
2134inline constexpr
2135month_weekday operator/(const weekday_indexed& __lhs, const month& __rhs) noexcept
2136{ return month_weekday{__rhs, __lhs}; }
2137
2138inline constexpr
2139month_weekday operator/(const weekday_indexed& __lhs, int __rhs) noexcept
2140{ return month_weekday{month(__rhs), __lhs}; }
2141
2142
2143class _LIBCPP_TYPE_VIS month_weekday_last {
2144    chrono::month        __m;
2145    chrono::weekday_last __wdl;
2146  public:
2147    constexpr month_weekday_last(const chrono::month& __mval, const chrono::weekday_last& __wdlval) noexcept
2148        : __m{__mval}, __wdl{__wdlval} {}
2149    inline constexpr chrono::month               month() const noexcept { return __m; }
2150    inline constexpr chrono::weekday_last weekday_last() const noexcept { return __wdl; }
2151    inline constexpr bool                           ok() const noexcept { return __m.ok() && __wdl.ok(); }
2152};
2153
2154inline constexpr
2155bool operator==(const month_weekday_last& __lhs, const month_weekday_last& __rhs) noexcept
2156{ return __lhs.month() == __rhs.month() && __lhs.weekday_last() == __rhs.weekday_last(); }
2157
2158inline constexpr
2159bool operator!=(const month_weekday_last& __lhs, const month_weekday_last& __rhs) noexcept
2160{ return !(__lhs == __rhs); }
2161
2162
2163inline constexpr
2164month_weekday_last operator/(const month& __lhs, const weekday_last& __rhs) noexcept
2165{ return month_weekday_last{__lhs, __rhs}; }
2166
2167inline constexpr
2168month_weekday_last operator/(int __lhs, const weekday_last& __rhs) noexcept
2169{ return month_weekday_last{month(__lhs), __rhs}; }
2170
2171inline constexpr
2172month_weekday_last operator/(const weekday_last& __lhs, const month& __rhs) noexcept
2173{ return month_weekday_last{__rhs, __lhs}; }
2174
2175inline constexpr
2176month_weekday_last operator/(const weekday_last& __lhs, int __rhs) noexcept
2177{ return month_weekday_last{month(__rhs), __lhs}; }
2178
2179
2180class _LIBCPP_TYPE_VIS year_month {
2181    chrono::year  __y;
2182    chrono::month __m;
2183public:
2184    year_month() = default;
2185    constexpr year_month(const chrono::year& __yval, const chrono::month& __mval) noexcept
2186        : __y{__yval}, __m{__mval} {}
2187    inline constexpr chrono::year  year()  const noexcept { return __y; }
2188    inline constexpr chrono::month month() const noexcept { return __m; }
2189    inline constexpr year_month& operator+=(const months& __dm) noexcept { this->__m += __dm; return *this; }
2190    inline constexpr year_month& operator-=(const months& __dm) noexcept { this->__m -= __dm; return *this; }
2191    inline constexpr year_month& operator+=(const years& __dy)  noexcept { this->__y += __dy; return *this; }
2192    inline constexpr year_month& operator-=(const years& __dy)  noexcept { this->__y -= __dy; return *this; }
2193    inline constexpr bool ok() const noexcept { return __y.ok() && __m.ok(); }
2194};
2195
2196inline constexpr
2197year_month operator/(const year& __y, const month& __m) noexcept { return year_month{__y, __m}; }
2198
2199inline constexpr
2200year_month operator/(const year& __y, int __m) noexcept { return year_month{__y, month(__m)}; }
2201
2202inline constexpr
2203bool operator==(const year_month& __lhs, const year_month& __rhs) noexcept
2204{ return __lhs.year() == __rhs.year() && __lhs.month() == __rhs.month(); }
2205
2206inline constexpr
2207bool operator!=(const year_month& __lhs, const year_month& __rhs) noexcept
2208{ return !(__lhs == __rhs); }
2209
2210inline constexpr
2211bool operator< (const year_month& __lhs, const year_month& __rhs) noexcept
2212{ return __lhs.year() != __rhs.year() ? __lhs.year() < __rhs.year() : __lhs.month() < __rhs.month(); }
2213
2214inline constexpr
2215bool operator> (const year_month& __lhs, const year_month& __rhs) noexcept
2216{ return __rhs < __lhs; }
2217
2218inline constexpr
2219bool operator<=(const year_month& __lhs, const year_month& __rhs) noexcept
2220{ return !(__rhs < __lhs);}
2221
2222inline constexpr
2223bool operator>=(const year_month& __lhs, const year_month& __rhs) noexcept
2224{ return !(__lhs < __rhs); }
2225
2226constexpr year_month operator+(const year_month& __lhs, const months& __rhs) noexcept
2227{
2228    int __dmi = static_cast<int>(static_cast<unsigned>(__lhs.month())) - 1 + __rhs.count();
2229    const int __dy = (__dmi >= 0 ? __dmi : __dmi-11) / 12;
2230    __dmi = __dmi - __dy * 12 + 1;
2231    return (__lhs.year() + years(__dy)) / month(static_cast<unsigned>(__dmi));
2232}
2233
2234constexpr year_month operator+(const months& __lhs, const year_month& __rhs) noexcept
2235{ return __rhs + __lhs; }
2236
2237constexpr year_month operator+(const year_month& __lhs, const years& __rhs) noexcept
2238{ return (__lhs.year() + __rhs) / __lhs.month(); }
2239
2240constexpr year_month operator+(const years& __lhs, const year_month& __rhs) noexcept
2241{ return __rhs + __lhs; }
2242
2243constexpr months     operator-(const year_month& __lhs, const year_month& __rhs) noexcept
2244{ return (__lhs.year() - __rhs.year()) + months(static_cast<unsigned>(__lhs.month()) - static_cast<unsigned>(__rhs.month())); }
2245
2246constexpr year_month operator-(const year_month& __lhs, const months& __rhs) noexcept
2247{ return __lhs + -__rhs; }
2248
2249constexpr year_month operator-(const year_month& __lhs, const years& __rhs) noexcept
2250{ return __lhs + -__rhs; }
2251
2252class year_month_day_last;
2253
2254class _LIBCPP_TYPE_VIS year_month_day {
2255private:
2256    chrono::year  __y;
2257    chrono::month __m;
2258    chrono::day   __d;
2259public:
2260     year_month_day() = default;
2261     inline constexpr year_month_day(
2262            const chrono::year& __yval, const chrono::month& __mval, const chrono::day& __dval) noexcept
2263            : __y{__yval}, __m{__mval}, __d{__dval} {}
2264            constexpr year_month_day(const year_month_day_last& __ymdl) noexcept;
2265     inline constexpr year_month_day(const sys_days& __sysd) noexcept
2266            : year_month_day(__from_days(__sysd.time_since_epoch())) {}
2267     inline explicit constexpr year_month_day(const local_days& __locd) noexcept
2268            : year_month_day(__from_days(__locd.time_since_epoch())) {}
2269
2270            constexpr year_month_day& operator+=(const months& __dm) noexcept;
2271            constexpr year_month_day& operator-=(const months& __dm) noexcept;
2272            constexpr year_month_day& operator+=(const years& __dy)  noexcept;
2273            constexpr year_month_day& operator-=(const years& __dy)  noexcept;
2274
2275     inline constexpr chrono::year   year() const noexcept { return __y; }
2276     inline constexpr chrono::month month() const noexcept { return __m; }
2277     inline constexpr chrono::day     day() const noexcept { return __d; }
2278     inline constexpr operator   sys_days() const noexcept          { return   sys_days{__to_days()}; }
2279     inline explicit constexpr operator local_days() const noexcept { return local_days{__to_days()}; }
2280
2281            constexpr bool             ok() const noexcept;
2282
2283     static constexpr year_month_day __from_days(days __d) noexcept;
2284     constexpr days __to_days() const noexcept;
2285};
2286
2287
2288// https://howardhinnant.github.io/date_algorithms.html#civil_from_days
2289inline constexpr
2290year_month_day
2291year_month_day::__from_days(days __d) noexcept
2292{
2293    static_assert(std::numeric_limits<unsigned>::digits >= 18, "");
2294    static_assert(std::numeric_limits<int>::digits >= 20     , "");
2295    const int      __z = __d.count() + 719468;
2296    const int      __era = (__z >= 0 ? __z : __z - 146096) / 146097;
2297    const unsigned __doe = static_cast<unsigned>(__z - __era * 146097);              // [0, 146096]
2298    const unsigned __yoe = (__doe - __doe/1460 + __doe/36524 - __doe/146096) / 365;  // [0, 399]
2299    const int      __yr = static_cast<int>(__yoe) + __era * 400;
2300    const unsigned __doy = __doe - (365 * __yoe + __yoe/4 - __yoe/100);              // [0, 365]
2301    const unsigned __mp = (5 * __doy + 2)/153;                                       // [0, 11]
2302    const unsigned __dy = __doy - (153 * __mp + 2)/5 + 1;                            // [1, 31]
2303    const unsigned __mth = __mp + (__mp < 10 ? 3 : -9);                              // [1, 12]
2304    return year_month_day{chrono::year{__yr + (__mth <= 2)}, chrono::month{__mth}, chrono::day{__dy}};
2305}
2306
2307// https://howardhinnant.github.io/date_algorithms.html#days_from_civil
2308inline constexpr days year_month_day::__to_days() const noexcept
2309{
2310    static_assert(std::numeric_limits<unsigned>::digits >= 18, "");
2311    static_assert(std::numeric_limits<int>::digits >= 20     , "");
2312
2313    const int      __yr  = static_cast<int>(__y) - (__m <= February);
2314    const unsigned __mth = static_cast<unsigned>(__m);
2315    const unsigned __dy  = static_cast<unsigned>(__d);
2316
2317    const int      __era = (__yr >= 0 ? __yr : __yr - 399) / 400;
2318    const unsigned __yoe = static_cast<unsigned>(__yr - __era * 400);                // [0, 399]
2319    const unsigned __doy = (153 * (__mth + (__mth > 2 ? -3 : 9)) + 2) / 5 + __dy-1;  // [0, 365]
2320    const unsigned __doe = __yoe * 365 + __yoe/4 - __yoe/100 + __doy;                // [0, 146096]
2321    return days{__era * 146097 + static_cast<int>(__doe) - 719468};
2322}
2323
2324inline constexpr
2325bool operator==(const year_month_day& __lhs, const year_month_day& __rhs) noexcept
2326{ return __lhs.year() == __rhs.year() && __lhs.month() == __rhs.month() && __lhs.day() == __rhs.day(); }
2327
2328inline constexpr
2329bool operator!=(const year_month_day& __lhs, const year_month_day& __rhs) noexcept
2330{ return !(__lhs == __rhs); }
2331
2332inline constexpr
2333bool operator< (const year_month_day& __lhs, const year_month_day& __rhs) noexcept
2334{
2335    if (__lhs.year() < __rhs.year()) return true;
2336    if (__lhs.year() > __rhs.year()) return false;
2337    if (__lhs.month() < __rhs.month()) return true;
2338    if (__lhs.month() > __rhs.month()) return false;
2339    return __lhs.day() < __rhs.day();
2340}
2341
2342inline constexpr
2343bool operator> (const year_month_day& __lhs, const year_month_day& __rhs) noexcept
2344{ return __rhs < __lhs; }
2345
2346inline constexpr
2347bool operator<=(const year_month_day& __lhs, const year_month_day& __rhs) noexcept
2348{ return !(__rhs < __lhs);}
2349
2350inline constexpr
2351bool operator>=(const year_month_day& __lhs, const year_month_day& __rhs) noexcept
2352{ return !(__lhs < __rhs); }
2353
2354inline constexpr
2355year_month_day operator/(const year_month& __lhs, const day& __rhs) noexcept
2356{ return year_month_day{__lhs.year(), __lhs.month(), __rhs}; }
2357
2358inline constexpr
2359year_month_day operator/(const year_month& __lhs, int __rhs) noexcept
2360{ return __lhs / day(__rhs); }
2361
2362inline constexpr
2363year_month_day operator/(const year& __lhs, const month_day& __rhs) noexcept
2364{ return __lhs / __rhs.month() / __rhs.day(); }
2365
2366inline constexpr
2367year_month_day operator/(int __lhs, const month_day& __rhs) noexcept
2368{ return year(__lhs) / __rhs; }
2369
2370inline constexpr
2371year_month_day operator/(const month_day& __lhs, const year& __rhs) noexcept
2372{ return __rhs / __lhs; }
2373
2374inline constexpr
2375year_month_day operator/(const month_day& __lhs, int __rhs) noexcept
2376{ return year(__rhs) / __lhs; }
2377
2378
2379inline constexpr
2380year_month_day operator+(const year_month_day& __lhs, const months& __rhs) noexcept
2381{ return (__lhs.year()/__lhs.month() + __rhs)/__lhs.day(); }
2382
2383inline constexpr
2384year_month_day operator+(const months& __lhs, const year_month_day& __rhs) noexcept
2385{ return __rhs + __lhs; }
2386
2387inline constexpr
2388year_month_day operator-(const year_month_day& __lhs, const months& __rhs) noexcept
2389{ return __lhs + -__rhs; }
2390
2391inline constexpr
2392year_month_day operator+(const year_month_day& __lhs, const years& __rhs) noexcept
2393{ return (__lhs.year() + __rhs) / __lhs.month() / __lhs.day(); }
2394
2395inline constexpr
2396year_month_day operator+(const years& __lhs, const year_month_day& __rhs) noexcept
2397{ return __rhs + __lhs; }
2398
2399inline constexpr
2400year_month_day operator-(const year_month_day& __lhs, const years& __rhs) noexcept
2401{ return __lhs + -__rhs; }
2402
2403inline constexpr year_month_day& year_month_day::operator+=(const months& __dm) noexcept { *this = *this + __dm; return *this; }
2404inline constexpr year_month_day& year_month_day::operator-=(const months& __dm) noexcept { *this = *this - __dm; return *this; }
2405inline constexpr year_month_day& year_month_day::operator+=(const years& __dy)  noexcept { *this = *this + __dy; return *this; }
2406inline constexpr year_month_day& year_month_day::operator-=(const years& __dy)  noexcept { *this = *this - __dy; return *this; }
2407
2408class _LIBCPP_TYPE_VIS year_month_day_last {
2409private:
2410    chrono::year           __y;
2411    chrono::month_day_last __mdl;
2412public:
2413     constexpr year_month_day_last(const year& __yval, const month_day_last& __mdlval) noexcept
2414        : __y{__yval}, __mdl{__mdlval} {}
2415
2416     constexpr year_month_day_last& operator+=(const months& __m) noexcept;
2417     constexpr year_month_day_last& operator-=(const months& __m) noexcept;
2418     constexpr year_month_day_last& operator+=(const years& __y)  noexcept;
2419     constexpr year_month_day_last& operator-=(const years& __y)  noexcept;
2420
2421     inline constexpr chrono::year                     year() const noexcept { return __y; }
2422     inline constexpr chrono::month                   month() const noexcept { return __mdl.month(); }
2423     inline constexpr chrono::month_day_last month_day_last() const noexcept { return __mdl; }
2424            constexpr chrono::day                       day() const noexcept;
2425     inline constexpr operator                     sys_days() const noexcept { return   sys_days{year()/month()/day()}; }
2426     inline explicit constexpr operator          local_days() const noexcept { return local_days{year()/month()/day()}; }
2427     inline constexpr bool                               ok() const noexcept { return __y.ok() && __mdl.ok(); }
2428};
2429
2430inline constexpr
2431chrono::day year_month_day_last::day() const noexcept
2432{
2433    constexpr chrono::day __d[] =
2434    {
2435        chrono::day(31), chrono::day(28), chrono::day(31),
2436        chrono::day(30), chrono::day(31), chrono::day(30),
2437        chrono::day(31), chrono::day(31), chrono::day(30),
2438        chrono::day(31), chrono::day(30), chrono::day(31)
2439    };
2440    return month() != February || !__y.is_leap() ?
2441        __d[static_cast<unsigned>(month()) - 1] : chrono::day{29};
2442}
2443
2444inline constexpr
2445bool operator==(const year_month_day_last& __lhs, const year_month_day_last& __rhs) noexcept
2446{ return __lhs.year() == __rhs.year() && __lhs.month_day_last() == __rhs.month_day_last(); }
2447
2448inline constexpr
2449bool operator!=(const year_month_day_last& __lhs, const year_month_day_last& __rhs) noexcept
2450{ return !(__lhs == __rhs); }
2451
2452inline constexpr
2453bool operator< (const year_month_day_last& __lhs, const year_month_day_last& __rhs) noexcept
2454{
2455    if (__lhs.year() < __rhs.year()) return true;
2456    if (__lhs.year() > __rhs.year()) return false;
2457    return __lhs.month_day_last() < __rhs.month_day_last();
2458}
2459
2460inline constexpr
2461bool operator> (const year_month_day_last& __lhs, const year_month_day_last& __rhs) noexcept
2462{ return __rhs < __lhs; }
2463
2464inline constexpr
2465bool operator<=(const year_month_day_last& __lhs, const year_month_day_last& __rhs) noexcept
2466{ return !(__rhs < __lhs);}
2467
2468inline constexpr
2469bool operator>=(const year_month_day_last& __lhs, const year_month_day_last& __rhs) noexcept
2470{ return !(__lhs < __rhs); }
2471
2472inline constexpr year_month_day_last operator/(const year_month& __lhs, last_spec) noexcept
2473{ return year_month_day_last{__lhs.year(), month_day_last{__lhs.month()}}; }
2474
2475inline constexpr year_month_day_last operator/(const year& __lhs, const month_day_last& __rhs) noexcept
2476{ return year_month_day_last{__lhs, __rhs}; }
2477
2478inline constexpr year_month_day_last operator/(int __lhs, const month_day_last& __rhs) noexcept
2479{ return year_month_day_last{year{__lhs}, __rhs}; }
2480
2481inline constexpr year_month_day_last operator/(const month_day_last& __lhs, const year& __rhs) noexcept
2482{ return __rhs / __lhs; }
2483
2484inline constexpr year_month_day_last operator/(const month_day_last& __lhs, int __rhs) noexcept
2485{ return year{__rhs} / __lhs; }
2486
2487
2488inline constexpr
2489year_month_day_last operator+(const year_month_day_last& __lhs, const months& __rhs) noexcept
2490{ return (__lhs.year() / __lhs.month() + __rhs) / last; }
2491
2492inline constexpr
2493year_month_day_last operator+(const months& __lhs, const year_month_day_last& __rhs) noexcept
2494{ return __rhs + __lhs; }
2495
2496inline constexpr
2497year_month_day_last operator-(const year_month_day_last& __lhs, const months& __rhs) noexcept
2498{ return __lhs + (-__rhs); }
2499
2500inline constexpr
2501year_month_day_last operator+(const year_month_day_last& __lhs, const years& __rhs) noexcept
2502{ return year_month_day_last{__lhs.year() + __rhs, __lhs.month_day_last()}; }
2503
2504inline constexpr
2505year_month_day_last operator+(const years& __lhs, const year_month_day_last& __rhs) noexcept
2506{ return __rhs + __lhs; }
2507
2508inline constexpr
2509year_month_day_last operator-(const year_month_day_last& __lhs, const years& __rhs) noexcept
2510{ return __lhs + (-__rhs); }
2511
2512inline constexpr year_month_day_last& year_month_day_last::operator+=(const months& __dm) noexcept { *this = *this + __dm; return *this; }
2513inline constexpr year_month_day_last& year_month_day_last::operator-=(const months& __dm) noexcept { *this = *this - __dm; return *this; }
2514inline constexpr year_month_day_last& year_month_day_last::operator+=(const years& __dy)  noexcept { *this = *this + __dy; return *this; }
2515inline constexpr year_month_day_last& year_month_day_last::operator-=(const years& __dy)  noexcept { *this = *this - __dy; return *this; }
2516
2517inline constexpr year_month_day::year_month_day(const year_month_day_last& __ymdl) noexcept
2518    : __y{__ymdl.year()}, __m{__ymdl.month()}, __d{__ymdl.day()} {}
2519
2520inline constexpr bool year_month_day::ok() const noexcept
2521{
2522    if (!__y.ok() || !__m.ok()) return false;
2523    return chrono::day{1} <= __d && __d <= (__y / __m / last).day();
2524}
2525
2526class _LIBCPP_TYPE_VIS year_month_weekday {
2527    chrono::year            __y;
2528    chrono::month           __m;
2529    chrono::weekday_indexed __wdi;
2530public:
2531    year_month_weekday() = default;
2532    constexpr year_month_weekday(const chrono::year& __yval, const chrono::month& __mval,
2533                               const chrono::weekday_indexed& __wdival) noexcept
2534        : __y{__yval}, __m{__mval}, __wdi{__wdival} {}
2535    constexpr year_month_weekday(const sys_days& __sysd) noexcept
2536            : year_month_weekday(__from_days(__sysd.time_since_epoch())) {}
2537    inline explicit constexpr year_month_weekday(const local_days& __locd) noexcept
2538            : year_month_weekday(__from_days(__locd.time_since_epoch())) {}
2539    constexpr year_month_weekday& operator+=(const months& m) noexcept;
2540    constexpr year_month_weekday& operator-=(const months& m) noexcept;
2541    constexpr year_month_weekday& operator+=(const years& y)  noexcept;
2542    constexpr year_month_weekday& operator-=(const years& y)  noexcept;
2543
2544    inline constexpr chrono::year                       year() const noexcept { return __y; }
2545    inline constexpr chrono::month                     month() const noexcept { return __m; }
2546    inline constexpr chrono::weekday                 weekday() const noexcept { return __wdi.weekday(); }
2547    inline constexpr unsigned                          index() const noexcept { return __wdi.index(); }
2548    inline constexpr chrono::weekday_indexed weekday_indexed() const noexcept { return __wdi; }
2549
2550    inline constexpr                       operator sys_days() const noexcept { return   sys_days{__to_days()}; }
2551    inline explicit constexpr operator            local_days() const noexcept { return local_days{__to_days()}; }
2552    inline constexpr bool ok() const noexcept
2553    {
2554        if (!__y.ok() || !__m.ok() || !__wdi.ok()) return false;
2555    //  TODO: make sure it's a valid date
2556        return true;
2557    }
2558
2559    static constexpr year_month_weekday __from_days(days __d) noexcept;
2560    constexpr days __to_days() const noexcept;
2561};
2562
2563inline constexpr
2564year_month_weekday year_month_weekday::__from_days(days __d) noexcept
2565{
2566    const sys_days      __sysd{__d};
2567    const chrono::weekday __wd = chrono::weekday(__sysd);
2568    const year_month_day __ymd = year_month_day(__sysd);
2569    return year_month_weekday{__ymd.year(), __ymd.month(),
2570                              __wd[(static_cast<unsigned>(__ymd.day())-1)/7+1]};
2571}
2572
2573inline constexpr
2574days year_month_weekday::__to_days() const noexcept
2575{
2576    const sys_days __sysd = sys_days(__y/__m/1);
2577    return (__sysd + (__wdi.weekday() - chrono::weekday(__sysd) + days{(__wdi.index()-1)*7}))
2578                .time_since_epoch();
2579}
2580
2581inline constexpr
2582bool operator==(const year_month_weekday& __lhs, const year_month_weekday& __rhs) noexcept
2583{ return __lhs.year() == __rhs.year() && __lhs.month() == __rhs.month() && __lhs.weekday_indexed() == __rhs.weekday_indexed(); }
2584
2585inline constexpr
2586bool operator!=(const year_month_weekday& __lhs, const year_month_weekday& __rhs) noexcept
2587{ return !(__lhs == __rhs); }
2588
2589inline constexpr
2590year_month_weekday operator/(const year_month& __lhs, const weekday_indexed& __rhs) noexcept
2591{ return year_month_weekday{__lhs.year(), __lhs.month(), __rhs}; }
2592
2593inline constexpr
2594year_month_weekday operator/(const year& __lhs, const month_weekday& __rhs) noexcept
2595{ return year_month_weekday{__lhs, __rhs.month(), __rhs.weekday_indexed()}; }
2596
2597inline constexpr
2598year_month_weekday operator/(int __lhs, const month_weekday& __rhs) noexcept
2599{ return year(__lhs) / __rhs; }
2600
2601inline constexpr
2602year_month_weekday operator/(const month_weekday& __lhs, const year& __rhs) noexcept
2603{ return __rhs / __lhs; }
2604
2605inline constexpr
2606year_month_weekday operator/(const month_weekday& __lhs, int __rhs) noexcept
2607{ return year(__rhs) / __lhs; }
2608
2609
2610inline constexpr
2611year_month_weekday operator+(const year_month_weekday& __lhs, const months& __rhs) noexcept
2612{ return (__lhs.year() / __lhs.month() + __rhs) / __lhs.weekday_indexed(); }
2613
2614inline constexpr
2615year_month_weekday operator+(const months& __lhs, const year_month_weekday& __rhs) noexcept
2616{ return __rhs + __lhs; }
2617
2618inline constexpr
2619year_month_weekday operator-(const year_month_weekday& __lhs, const months& __rhs) noexcept
2620{ return __lhs + (-__rhs); }
2621
2622inline constexpr
2623year_month_weekday operator+(const year_month_weekday& __lhs, const years& __rhs) noexcept
2624{ return year_month_weekday{__lhs.year() + __rhs, __lhs.month(), __lhs.weekday_indexed()}; }
2625
2626inline constexpr
2627year_month_weekday operator+(const years& __lhs, const year_month_weekday& __rhs) noexcept
2628{ return __rhs + __lhs; }
2629
2630inline constexpr
2631year_month_weekday operator-(const year_month_weekday& __lhs, const years& __rhs) noexcept
2632{ return __lhs + (-__rhs); }
2633
2634
2635inline constexpr year_month_weekday& year_month_weekday::operator+=(const months& __dm) noexcept { *this = *this + __dm; return *this; }
2636inline constexpr year_month_weekday& year_month_weekday::operator-=(const months& __dm) noexcept { *this = *this - __dm; return *this; }
2637inline constexpr year_month_weekday& year_month_weekday::operator+=(const years& __dy)  noexcept { *this = *this + __dy; return *this; }
2638inline constexpr year_month_weekday& year_month_weekday::operator-=(const years& __dy)  noexcept { *this = *this - __dy; return *this; }
2639
2640class _LIBCPP_TYPE_VIS year_month_weekday_last {
2641private:
2642    chrono::year         __y;
2643    chrono::month        __m;
2644    chrono::weekday_last __wdl;
2645public:
2646    constexpr year_month_weekday_last(const chrono::year& __yval, const chrono::month& __mval,
2647                                      const chrono::weekday_last& __wdlval) noexcept
2648                : __y{__yval}, __m{__mval}, __wdl{__wdlval} {}
2649    constexpr year_month_weekday_last& operator+=(const months& __dm) noexcept;
2650    constexpr year_month_weekday_last& operator-=(const months& __dm) noexcept;
2651    constexpr year_month_weekday_last& operator+=(const years& __dy)  noexcept;
2652    constexpr year_month_weekday_last& operator-=(const years& __dy)  noexcept;
2653
2654    inline constexpr chrono::year                 year() const noexcept { return __y; }
2655    inline constexpr chrono::month               month() const noexcept { return __m; }
2656    inline constexpr chrono::weekday           weekday() const noexcept { return __wdl.weekday(); }
2657    inline constexpr chrono::weekday_last weekday_last() const noexcept { return __wdl; }
2658    inline constexpr operator                 sys_days() const noexcept { return   sys_days{__to_days()}; }
2659    inline explicit constexpr operator      local_days() const noexcept { return local_days{__to_days()}; }
2660    inline constexpr bool ok() const noexcept { return __y.ok() && __m.ok() && __wdl.ok(); }
2661
2662    constexpr days __to_days() const noexcept;
2663
2664};
2665
2666inline constexpr
2667days year_month_weekday_last::__to_days() const noexcept
2668{
2669    const sys_days __last = sys_days{__y/__m/last};
2670    return (__last - (chrono::weekday{__last} - __wdl.weekday())).time_since_epoch();
2671
2672}
2673
2674inline constexpr
2675bool operator==(const year_month_weekday_last& __lhs, const year_month_weekday_last& __rhs) noexcept
2676{ return __lhs.year() == __rhs.year() && __lhs.month() == __rhs.month() && __lhs.weekday_last() == __rhs.weekday_last(); }
2677
2678inline constexpr
2679bool operator!=(const year_month_weekday_last& __lhs, const year_month_weekday_last& __rhs) noexcept
2680{ return !(__lhs == __rhs); }
2681
2682
2683inline constexpr
2684year_month_weekday_last operator/(const year_month& __lhs, const weekday_last& __rhs) noexcept
2685{ return year_month_weekday_last{__lhs.year(), __lhs.month(), __rhs}; }
2686
2687inline constexpr
2688year_month_weekday_last operator/(const year& __lhs, const month_weekday_last& __rhs) noexcept
2689{ return year_month_weekday_last{__lhs, __rhs.month(), __rhs.weekday_last()}; }
2690
2691inline constexpr
2692year_month_weekday_last operator/(int __lhs, const month_weekday_last& __rhs) noexcept
2693{ return year(__lhs) / __rhs; }
2694
2695inline constexpr
2696year_month_weekday_last operator/(const month_weekday_last& __lhs, const year& __rhs) noexcept
2697{ return __rhs / __lhs; }
2698
2699inline constexpr
2700year_month_weekday_last operator/(const month_weekday_last& __lhs, int __rhs) noexcept
2701{ return year(__rhs) / __lhs; }
2702
2703
2704inline constexpr
2705year_month_weekday_last operator+(const year_month_weekday_last& __lhs, const months& __rhs) noexcept
2706{ return (__lhs.year() / __lhs.month() + __rhs) / __lhs.weekday_last(); }
2707
2708inline constexpr
2709year_month_weekday_last operator+(const months& __lhs, const year_month_weekday_last& __rhs) noexcept
2710{ return __rhs + __lhs; }
2711
2712inline constexpr
2713year_month_weekday_last operator-(const year_month_weekday_last& __lhs, const months& __rhs) noexcept
2714{ return __lhs + (-__rhs); }
2715
2716inline constexpr
2717year_month_weekday_last operator+(const year_month_weekday_last& __lhs, const years& __rhs) noexcept
2718{ return year_month_weekday_last{__lhs.year() + __rhs, __lhs.month(), __lhs.weekday_last()}; }
2719
2720inline constexpr
2721year_month_weekday_last operator+(const years& __lhs, const year_month_weekday_last& __rhs) noexcept
2722{ return __rhs + __lhs; }
2723
2724inline constexpr
2725year_month_weekday_last operator-(const year_month_weekday_last& __lhs, const years& __rhs) noexcept
2726{ return __lhs + (-__rhs); }
2727
2728inline constexpr year_month_weekday_last& year_month_weekday_last::operator+=(const months& __dm) noexcept { *this = *this + __dm; return *this; }
2729inline constexpr year_month_weekday_last& year_month_weekday_last::operator-=(const months& __dm) noexcept { *this = *this - __dm; return *this; }
2730inline constexpr year_month_weekday_last& year_month_weekday_last::operator+=(const years& __dy)  noexcept { *this = *this + __dy; return *this; }
2731inline constexpr year_month_weekday_last& year_month_weekday_last::operator-=(const years& __dy)  noexcept { *this = *this - __dy; return *this; }
2732
2733#endif // _LIBCPP_STD_VER > 17
2734} // chrono
2735
2736#if _LIBCPP_STD_VER > 11
2737// Suffixes for duration literals [time.duration.literals]
2738inline namespace literals
2739{
2740  inline namespace chrono_literals
2741  {
2742
2743    constexpr chrono::hours operator""h(unsigned long long __h)
2744    {
2745        return chrono::hours(static_cast<chrono::hours::rep>(__h));
2746    }
2747
2748    constexpr chrono::duration<long double, ratio<3600,1>> operator""h(long double __h)
2749    {
2750        return chrono::duration<long double, ratio<3600,1>>(__h);
2751    }
2752
2753
2754    constexpr chrono::minutes operator""min(unsigned long long __m)
2755    {
2756        return chrono::minutes(static_cast<chrono::minutes::rep>(__m));
2757    }
2758
2759    constexpr chrono::duration<long double, ratio<60,1>> operator""min(long double __m)
2760    {
2761        return chrono::duration<long double, ratio<60,1>> (__m);
2762    }
2763
2764
2765    constexpr chrono::seconds operator""s(unsigned long long __s)
2766    {
2767        return chrono::seconds(static_cast<chrono::seconds::rep>(__s));
2768    }
2769
2770    constexpr chrono::duration<long double> operator""s(long double __s)
2771    {
2772        return chrono::duration<long double> (__s);
2773    }
2774
2775
2776    constexpr chrono::milliseconds operator""ms(unsigned long long __ms)
2777    {
2778        return chrono::milliseconds(static_cast<chrono::milliseconds::rep>(__ms));
2779    }
2780
2781    constexpr chrono::duration<long double, milli> operator""ms(long double __ms)
2782    {
2783        return chrono::duration<long double, milli>(__ms);
2784    }
2785
2786
2787    constexpr chrono::microseconds operator""us(unsigned long long __us)
2788    {
2789        return chrono::microseconds(static_cast<chrono::microseconds::rep>(__us));
2790    }
2791
2792    constexpr chrono::duration<long double, micro> operator""us(long double __us)
2793    {
2794        return chrono::duration<long double, micro> (__us);
2795    }
2796
2797
2798    constexpr chrono::nanoseconds operator""ns(unsigned long long __ns)
2799    {
2800        return chrono::nanoseconds(static_cast<chrono::nanoseconds::rep>(__ns));
2801    }
2802
2803    constexpr chrono::duration<long double, nano> operator""ns(long double __ns)
2804    {
2805        return chrono::duration<long double, nano> (__ns);
2806    }
2807
2808#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CXX20_CHRONO_LITERALS)
2809    constexpr chrono::day operator ""d(unsigned long long __d) noexcept
2810    {
2811        return chrono::day(static_cast<unsigned>(__d));
2812    }
2813
2814    constexpr chrono::year operator ""y(unsigned long long __y) noexcept
2815    {
2816        return chrono::year(static_cast<int>(__y));
2817    }
2818#endif
2819}}
2820
2821namespace chrono { // hoist the literals into namespace std::chrono
2822   using namespace literals::chrono_literals;
2823}
2824
2825#endif
2826
2827_LIBCPP_END_NAMESPACE_STD
2828
2829#ifndef _LIBCPP_CXX03_LANG
2830_LIBCPP_BEGIN_NAMESPACE_FILESYSTEM
2831struct _FilesystemClock {
2832#if !defined(_LIBCPP_HAS_NO_INT128)
2833  typedef __int128_t rep;
2834  typedef nano period;
2835#else
2836  typedef long long rep;
2837  typedef nano period;
2838#endif
2839
2840  typedef chrono::duration<rep, period> duration;
2841  typedef chrono::time_point<_FilesystemClock> time_point;
2842
2843  static _LIBCPP_CONSTEXPR_AFTER_CXX11 const bool is_steady = false;
2844
2845  _LIBCPP_FUNC_VIS static time_point now() noexcept;
2846
2847  _LIBCPP_INLINE_VISIBILITY
2848  static time_t to_time_t(const time_point& __t) noexcept {
2849      typedef chrono::duration<rep> __secs;
2850      return time_t(
2851          chrono::duration_cast<__secs>(__t.time_since_epoch()).count());
2852  }
2853
2854  _LIBCPP_INLINE_VISIBILITY
2855  static time_point from_time_t(time_t __t) noexcept {
2856      typedef chrono::duration<rep> __secs;
2857      return time_point(__secs(__t));
2858  }
2859};
2860_LIBCPP_END_NAMESPACE_FILESYSTEM
2861#endif // !_LIBCPP_CXX03_LANG
2862
2863_LIBCPP_POP_MACROS
2864
2865#endif  // _LIBCPP_CHRONO
2866