xref: /llvm-project/libcxx/include/chrono (revision 0cd794d4860e376698bb4da24bcdf8cbf331835c)
1// -*- C++ -*-
2//===----------------------------------------------------------------------===//
3//
4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5// See https://llvm.org/LICENSE.txt for license information.
6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef _LIBCPP_CHRONO
11#define _LIBCPP_CHRONO
12
13// clang-format off
14
15/*
16    chrono synopsis
17
18#include <compare> // C++20
19
20namespace std
21{
22namespace chrono
23{
24
25template <class ToDuration, class Rep, class Period>
26constexpr
27ToDuration
28duration_cast(const duration<Rep, Period>& fd);
29
30template <class Rep> struct treat_as_floating_point : is_floating_point<Rep> {};
31
32template <class Rep> inline constexpr bool treat_as_floating_point_v
33    = treat_as_floating_point<Rep>::value;                       // C++17
34
35template <class Rep>
36struct duration_values
37{
38public:
39    static constexpr Rep zero(); // noexcept in C++20
40    static constexpr Rep max();  // noexcept in C++20
41    static constexpr Rep min();  // noexcept in C++20
42};
43
44// duration
45
46template <class Rep, class Period = ratio<1>>
47class duration
48{
49    static_assert(!__is_duration<Rep>::value, "A duration representation can not be a duration");
50    static_assert(__is_ratio<Period>::value, "Second template parameter of duration must be a std::ratio");
51    static_assert(Period::num > 0, "duration period must be positive");
52public:
53    typedef Rep rep;
54    typedef typename _Period::type period;
55
56    constexpr duration() = default;
57    template <class Rep2>
58        constexpr explicit duration(const Rep2& r,
59            typename enable_if
60            <
61               is_convertible<const Rep2&, rep>::value &&
62               (treat_as_floating_point<rep>::value ||
63               !treat_as_floating_point<rep>::value && !treat_as_floating_point<Rep2>::value)
64            >::type* = 0);
65
66    // conversions
67    template <class Rep2, class Period2>
68        constexpr duration(const duration<Rep2, Period2>& d,
69            typename enable_if
70            <
71                treat_as_floating_point<rep>::value ||
72                ratio_divide<Period2, period>::type::den == 1
73            >::type* = 0);
74
75    // observer
76
77    constexpr rep count() const;
78
79    // arithmetic
80
81    constexpr common_type<duration>::type  operator+() const;
82    constexpr common_type<duration>::type  operator-() const;
83    constexpr duration& operator++();    // constexpr in C++17
84    constexpr duration  operator++(int); // constexpr in C++17
85    constexpr duration& operator--();    // constexpr in C++17
86    constexpr duration  operator--(int); // constexpr in C++17
87
88    constexpr duration& operator+=(const duration& d);  // constexpr in C++17
89    constexpr duration& operator-=(const duration& d);  // constexpr in C++17
90
91    duration& operator*=(const rep& rhs);       // constexpr in C++17
92    duration& operator/=(const rep& rhs);       // constexpr in C++17
93    duration& operator%=(const rep& rhs);       // constexpr in C++17
94    duration& operator%=(const duration& rhs);  // constexpr in C++17
95
96    // special values
97
98    static constexpr duration zero(); // noexcept in C++20
99    static constexpr duration min();  // noexcept in C++20
100    static constexpr duration max();  // noexcept in C++20
101};
102
103typedef duration<long long,         nano> nanoseconds;
104typedef duration<long long,        micro> microseconds;
105typedef duration<long long,        milli> milliseconds;
106typedef duration<long long              > seconds;
107typedef duration<     long, ratio<  60> > minutes;
108typedef duration<     long, ratio<3600> > hours;
109
110template <class Clock, class Duration = typename Clock::duration>
111class time_point
112{
113public:
114    typedef Clock                     clock;
115    typedef Duration                  duration;
116    typedef typename duration::rep    rep;
117    typedef typename duration::period period;
118private:
119    duration d_;  // exposition only
120
121public:
122    time_point();  // has value "epoch" // constexpr in C++14
123    explicit time_point(const duration& d);  // same as time_point() + d // constexpr in C++14
124
125    // conversions
126    template <class Duration2>
127       time_point(const time_point<clock, Duration2>& t); // constexpr in C++14
128
129    // observer
130
131    duration time_since_epoch() const; // constexpr in C++14
132
133    // arithmetic
134
135    time_point& operator+=(const duration& d); // constexpr in C++17
136    time_point& operator-=(const duration& d); // constexpr in C++17
137
138    // special values
139
140    static constexpr time_point min();  // noexcept in C++20
141    static constexpr time_point max();  // noexcept in C++20
142};
143
144} // chrono
145
146// common_type traits
147template <class Rep1, class Period1, class Rep2, class Period2>
148  struct common_type<chrono::duration<Rep1, Period1>, chrono::duration<Rep2, Period2>>;
149
150template <class Clock, class Duration1, class Duration2>
151  struct common_type<chrono::time_point<Clock, Duration1>, chrono::time_point<Clock, Duration2>>;
152
153namespace chrono {
154
155// duration arithmetic
156template <class Rep1, class Period1, class Rep2, class Period2>
157  constexpr
158  typename common_type<duration<Rep1, Period1>, duration<Rep2, Period2>>::type
159  operator+(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
160template <class Rep1, class Period1, class Rep2, class Period2>
161  constexpr
162  typename common_type<duration<Rep1, Period1>, duration<Rep2, Period2>>::type
163  operator-(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
164template <class Rep1, class Period, class Rep2>
165  constexpr
166  duration<typename common_type<Rep1, Rep2>::type, Period>
167  operator*(const duration<Rep1, Period>& d, const Rep2& s);
168template <class Rep1, class Period, class Rep2>
169  constexpr
170  duration<typename common_type<Rep1, Rep2>::type, Period>
171  operator*(const Rep1& s, const duration<Rep2, Period>& d);
172template <class Rep1, class Period, class Rep2>
173  constexpr
174  duration<typename common_type<Rep1, Rep2>::type, Period>
175  operator/(const duration<Rep1, Period>& d, const Rep2& s);
176template <class Rep1, class Period1, class Rep2, class Period2>
177  constexpr
178  typename common_type<Rep1, Rep2>::type
179  operator/(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
180
181// duration comparisons
182template <class Rep1, class Period1, class Rep2, class Period2>
183   constexpr
184   bool operator==(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
185template <class Rep1, class Period1, class Rep2, class Period2>
186   constexpr
187   bool operator!=(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs); // removed in C++20
188template <class Rep1, class Period1, class Rep2, class Period2>
189   constexpr
190   bool operator< (const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
191template <class Rep1, class Period1, class Rep2, class Period2>
192   constexpr
193   bool operator<=(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
194template <class Rep1, class Period1, class Rep2, class Period2>
195   constexpr
196   bool operator> (const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
197template <class Rep1, class Period1, class Rep2, class Period2>
198   constexpr
199   bool operator>=(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
200template<class Rep1, class Period1, class Rep2, class Period2>
201  requires three_way_comparable<typename CT::rep>
202  constexpr auto operator<=>(const duration<Rep1, Period1>& lhs,
203                             const duration<Rep2, Period2>& rhs);                           // since C++20
204
205// duration_cast
206template <class ToDuration, class Rep, class Period>
207  ToDuration duration_cast(const duration<Rep, Period>& d);
208
209template <class ToDuration, class Rep, class Period>
210    constexpr ToDuration floor(const duration<Rep, Period>& d);    // C++17
211template <class ToDuration, class Rep, class Period>
212    constexpr ToDuration ceil(const duration<Rep, Period>& d);     // C++17
213template <class ToDuration, class Rep, class Period>
214    constexpr ToDuration round(const duration<Rep, Period>& d);    // C++17
215
216// duration I/O
217template<class charT, class traits, class Rep, class Period>       // C++20
218  basic_ostream<charT, traits>&
219    operator<<(basic_ostream<charT, traits>& os,
220               const duration<Rep, Period>& d);
221
222// time_point arithmetic (all constexpr in C++14)
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 Rep1, class Period1, class Clock, class Duration2>
227  time_point<Clock, typename common_type<duration<Rep1, Period1>, Duration2>::type>
228  operator+(const duration<Rep1, Period1>& lhs, const time_point<Clock, Duration2>& rhs);
229template <class Clock, class Duration1, class Rep2, class Period2>
230  time_point<Clock, typename common_type<Duration1, duration<Rep2, Period2>>::type>
231  operator-(const time_point<Clock, Duration1>& lhs, const duration<Rep2, Period2>& rhs);
232template <class Clock, class Duration1, class Duration2>
233  typename common_type<Duration1, Duration2>::type
234  operator-(const time_point<Clock, Duration1>& lhs, const time_point<Clock, Duration2>& rhs);
235
236// time_point comparisons (all constexpr in C++14)
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); // removed in C++20
241template <class Clock, class Duration1, class Duration2>
242   bool operator< (const time_point<Clock, Duration1>& lhs, const time_point<Clock, Duration2>& rhs);
243template <class Clock, class Duration1, class Duration2>
244   bool operator<=(const time_point<Clock, Duration1>& lhs, const time_point<Clock, Duration2>& rhs);
245template <class Clock, class Duration1, class Duration2>
246   bool operator> (const time_point<Clock, Duration1>& lhs, const time_point<Clock, Duration2>& rhs);
247template <class Clock, class Duration1, class Duration2>
248   bool operator>=(const time_point<Clock, Duration1>& lhs, const time_point<Clock, Duration2>& rhs);
249template<class Clock, class Duration1,
250         three_way_comparable_with<Duration1> Duration2>
251  constexpr auto operator<=>(const time_point<Clock, Duration1>& lhs,
252                             const time_point<Clock, Duration2>& rhs);                                // since C++20
253
254// time_point_cast (constexpr in C++14)
255
256template <class ToDuration, class Clock, class Duration>
257  time_point<Clock, ToDuration> time_point_cast(const time_point<Clock, Duration>& t);
258
259template <class ToDuration, class Clock, class Duration>
260    constexpr time_point<Clock, ToDuration>
261    floor(const time_point<Clock, Duration>& tp);                  // C++17
262
263template <class ToDuration, class Clock, class Duration>
264    constexpr time_point<Clock, ToDuration>
265    ceil(const time_point<Clock, Duration>& tp);                   // C++17
266
267template <class ToDuration, class Clock, class Duration>
268    constexpr time_point<Clock, ToDuration>
269    round(const time_point<Clock, Duration>& tp);                  // C++17
270
271template <class Rep, class Period>
272    constexpr duration<Rep, Period> abs(duration<Rep, Period> d);  // C++17
273
274// Clocks
275
276class system_clock
277{
278public:
279    typedef microseconds                     duration;
280    typedef duration::rep                    rep;
281    typedef duration::period                 period;
282    typedef chrono::time_point<system_clock> time_point;
283    static const bool is_steady =            false; // constexpr in C++14
284
285    static time_point now() noexcept;
286    static time_t     to_time_t  (const time_point& __t) noexcept;
287    static time_point from_time_t(time_t __t) noexcept;
288};
289
290template <class Duration>
291  using sys_time  = time_point<system_clock, Duration>; // C++20
292using sys_seconds = sys_time<seconds>;                  // C++20
293using sys_days    = sys_time<days>;                     // C++20
294
295template<class charT, class traits, class Duration>     // C++20
296  basic_ostream<charT, traits>&
297    operator<<(basic_ostream<charT, traits>& os, const sys_time<Duration>& tp);
298
299template<class charT, class traits>                    // C++20
300  basic_ostream<charT, traits>&
301    operator<<(basic_ostream<charT, traits>& os, const sys_days& dp);
302
303// [time.clock.utc], class utc_clock
304class utc_clock {                                      // C++20
305public:
306    using rep                       = a signed arithmetic type;
307    using period                    = ratio<unspecified, unspecified>;
308    using duration                  = chrono::duration<rep, period>;
309    using time_point                = chrono::time_point<utc_clock>;
310    static constexpr bool is_steady = unspecified;
311
312    static time_point now();
313
314    template<class Duration>
315      static sys_time<common_type_t<Duration, seconds>>
316        to_sys(const utc_time<Duration>& t);
317    template<class Duration>
318      static utc_time<common_type_t<Duration, seconds>>
319        from_sys(const sys_time<Duration>& t);
320};
321
322template<class Duration>
323using utc_time  = time_point<utc_clock, Duration>;      // C++20
324using utc_seconds = utc_time<seconds>;                  // C++20
325
326template<class charT, class traits, class Duration>     // C++20
327  basic_ostream<charT, traits>&
328    operator<<(basic_ostream<charT, traits>& os, const utc_time<Duration>& t);
329
330struct leap_second_info {                               // C++20
331  bool    is_leap_second;
332  seconds elapsed;
333};
334
335template<class Duration>                                // C++20
336  leap_second_info get_leap_second_info(const utc_time<Duration>& ut);
337
338class file_clock                                        // C++20
339{
340public:
341    typedef see-below                      rep;
342    typedef nano                           period;
343    typedef chrono::duration<rep, period>  duration;
344    typedef chrono::time_point<file_clock> time_point;
345    static constexpr bool is_steady =      false;
346
347    static time_point now() noexcept;
348
349    template<class Duration>
350    static sys_time<see-below> to_sys(const file_time<Duration>&);
351
352    template<class Duration>
353    static file_time<see-below> from_sys(const sys_time<Duration>&);
354};
355
356template<class Duration>
357  using file_time = time_point<file_clock, Duration>;   // C++20
358
359template<class charT, class traits, class Duration>     // C++20
360  basic_ostream<charT, traits>&
361    operator<<(basic_ostream<charT, traits>& os, const file_time<Duration>& tp);
362
363class steady_clock
364{
365public:
366    typedef nanoseconds                                   duration;
367    typedef duration::rep                                 rep;
368    typedef duration::period                              period;
369    typedef chrono::time_point<steady_clock, duration>    time_point;
370    static const bool is_steady =                         true; // constexpr in C++14
371
372    static time_point now() noexcept;
373};
374
375typedef steady_clock high_resolution_clock;
376
377// 25.7.8, local time           // C++20
378struct local_t {};
379template<class Duration>
380  using local_time  = time_point<local_t, Duration>;
381using local_seconds = local_time<seconds>;
382using local_days    = local_time<days>;
383
384template<class charT, class traits, class Duration>     // C++20
385  basic_ostream<charT, traits>&
386    operator<<(basic_ostream<charT, traits>& os, const local_time<Duration>& tp);
387
388// 25.8.2, class last_spec    // C++20
389struct last_spec;
390
391// 25.8.3, class day          // C++20
392
393class day;
394constexpr bool operator==(const day& x, const day& y) noexcept;
395constexpr strong_ordering operator<=>(const day& x, const day& y) noexcept;
396constexpr day  operator+(const day&  x, const days& y) noexcept;
397constexpr day  operator+(const days& x, const day&  y) noexcept;
398constexpr day  operator-(const day&  x, const days& y) noexcept;
399constexpr days operator-(const day&  x, const day&  y) noexcept;
400template<class charT, class traits>
401  basic_ostream<charT, traits>&
402    operator<<(basic_ostream<charT, traits>& os, const day& d);
403
404// 25.8.4, class month    // C++20
405class month;
406constexpr bool operator==(const month& x, const month& y) noexcept;
407constexpr strong_ordering operator<=>(const month& x, const month& y) noexcept;
408
409constexpr month  operator+(const month&  x, const months& y) noexcept;
410constexpr month  operator+(const months& x,  const month& y) noexcept;
411constexpr month  operator-(const month&  x, const months& y) noexcept;
412constexpr months operator-(const month&  x,  const month& y) noexcept;
413template<class charT, class traits>
414  basic_ostream<charT, traits>&
415    operator<<(basic_ostream<charT, traits>& os, const month& m);
416
417// 25.8.5, class year    // C++20
418class year;
419constexpr bool operator==(const year& x, const year& y) noexcept;
420constexpr strong_ordering operator<=>(const year& x, const year& y) noexcept;
421
422constexpr year  operator+(const year&  x, const years& y) noexcept;
423constexpr year  operator+(const years& x, const year&  y) noexcept;
424constexpr year  operator-(const year&  x, const years& y) noexcept;
425constexpr years operator-(const year&  x, const year&  y) noexcept;
426template<class charT, class traits>
427  basic_ostream<charT, traits>&
428    operator<<(basic_ostream<charT, traits>& os, const year& y);
429
430// 25.8.6, class weekday    // C++20
431class weekday;
432
433constexpr bool operator==(const weekday& x, const weekday& y) noexcept;
434constexpr weekday operator+(const weekday& x, const days&    y) noexcept;
435constexpr weekday operator+(const days&    x, const weekday& y) noexcept;
436constexpr weekday operator-(const weekday& x, const days&    y) noexcept;
437constexpr days    operator-(const weekday& x, const weekday& y) noexcept;
438template<class charT, class traits>
439  basic_ostream<charT, traits>&
440    operator<<(basic_ostream<charT, traits>& os, const weekday& wd);
441
442// 25.8.7, class weekday_indexed    // C++20
443
444class weekday_indexed;
445constexpr bool operator==(const weekday_indexed& x, const weekday_indexed& y) noexcept;
446
447template<class charT, class traits>
448  basic_ostream<charT, traits>&
449    operator<<(basic_ostream<charT, traits>& os, const weekday_indexed& wdi);
450
451// 25.8.8, class weekday_last    // C++20
452class weekday_last;
453
454constexpr bool operator==(const weekday_last& x, const weekday_last& y) noexcept;
455
456template<class charT, class traits>
457  basic_ostream<charT, traits>&
458    operator<<(basic_ostream<charT, traits>& os, const weekday_last& wdl);
459
460// 25.8.9, class month_day    // C++20
461class month_day;
462
463constexpr bool operator==(const month_day& x, const month_day& y) noexcept;
464constexpr strong_ordering operator<=>(const month_day& x, const month_day& y) noexcept;
465
466template<class charT, class traits>
467  basic_ostream<charT, traits>&
468    operator<<(basic_ostream<charT, traits>& os, const month_day& md);
469
470// 25.8.10, class month_day_last    // C++20
471class month_day_last;
472
473constexpr bool operator==(const month_day_last& x, const month_day_last& y) noexcept;
474constexpr strong_ordering operator<=>(const month_day_last& x, const month_day_last& y) noexcept;
475
476template<class charT, class traits>
477  basic_ostream<charT, traits>&
478    operator<<(basic_ostream<charT, traits>& os, const month_day_last& mdl);
479
480// 25.8.11, class month_weekday    // C++20
481class month_weekday;
482
483constexpr bool operator==(const month_weekday& x, const month_weekday& y) noexcept;
484
485template<class charT, class traits>
486  basic_ostream<charT, traits>&
487    operator<<(basic_ostream<charT, traits>& os, const month_weekday& mwd);
488
489// 25.8.12, class month_weekday_last    // C++20
490class month_weekday_last;
491
492constexpr bool operator==(const month_weekday_last& x, const month_weekday_last& y) noexcept;
493
494template<class charT, class traits>
495  basic_ostream<charT, traits>&
496    operator<<(basic_ostream<charT, traits>& os, const month_weekday_last& mwdl);
497
498
499// 25.8.13, class year_month    // C++20
500class year_month;
501
502constexpr bool operator==(const year_month& x, const year_month& y) noexcept;
503constexpr strong_ordering operator<=>(const year_month& x, const year_month& y) noexcept;
504
505constexpr year_month operator+(const year_month& ym, const months& dm) noexcept;
506constexpr year_month operator+(const months& dm, const year_month& ym) noexcept;
507constexpr year_month operator-(const year_month& ym, const months& dm) noexcept;
508constexpr months operator-(const year_month& x, const year_month& y) noexcept;
509constexpr year_month operator+(const year_month& ym, const years& dy) noexcept;
510constexpr year_month operator+(const years& dy, const year_month& ym) noexcept;
511constexpr year_month operator-(const year_month& ym, const years& dy) noexcept;
512
513template<class charT, class traits>
514  basic_ostream<charT, traits>&
515    operator<<(basic_ostream<charT, traits>& os, const year_month& ym);
516
517// 25.8.14, class year_month_day class    // C++20
518year_month_day;
519
520constexpr bool operator==(const year_month_day& x, const year_month_day& y) noexcept;
521constexpr strong_ordering operator<=>(const year_month_day& x, const year_month_day& y) noexcept;
522
523constexpr year_month_day operator+(const year_month_day& ymd, const months& dm) noexcept;
524constexpr year_month_day operator+(const months& dm, const year_month_day& ymd) noexcept;
525constexpr year_month_day operator+(const year_month_day& ymd, const years& dy) noexcept;
526constexpr year_month_day operator+(const years& dy, const year_month_day& ymd) noexcept;
527constexpr year_month_day operator-(const year_month_day& ymd, const months& dm) noexcept;
528constexpr year_month_day operator-(const year_month_day& ymd, const years& dy) noexcept;
529
530template<class charT, class traits>
531  basic_ostream<charT, traits>&
532    operator<<(basic_ostream<charT, traits>& os, const year_month_day& ymd);
533
534// 25.8.15, class year_month_day_last    // C++20
535class year_month_day_last;
536
537constexpr bool operator==(const year_month_day_last& x, const year_month_day_last& y) noexcept;
538constexpr strong_ordering operator<=>(const year_month_day_last_day& x, const year_month_day_last_day& y) noexcept;
539
540constexpr year_month_day_last
541  operator+(const year_month_day_last& ymdl, const months& dm) noexcept;
542constexpr year_month_day_last
543  operator+(const months& dm, const year_month_day_last& ymdl) noexcept;
544constexpr year_month_day_last
545  operator+(const year_month_day_last& ymdl, const years& dy) noexcept;
546constexpr year_month_day_last
547  operator+(const years& dy, const year_month_day_last& ymdl) noexcept;
548constexpr year_month_day_last
549  operator-(const year_month_day_last& ymdl, const months& dm) noexcept;
550constexpr year_month_day_last
551  operator-(const year_month_day_last& ymdl, const years& dy) noexcept;
552
553template<class charT, class traits>
554  basic_ostream<charT, traits>&
555    operator<<(basic_ostream<charT, traits>& os, const year_month_day_last& ymdl);
556
557// 25.8.16, class year_month_weekday    // C++20
558class year_month_weekday;
559
560constexpr bool operator==(const year_month_weekday& x,
561                          const year_month_weekday& y) noexcept;
562
563constexpr year_month_weekday
564  operator+(const year_month_weekday& ymwd, const months& dm) noexcept;
565constexpr year_month_weekday
566  operator+(const months& dm, const year_month_weekday& ymwd) noexcept;
567constexpr year_month_weekday
568  operator+(const year_month_weekday& ymwd, const years& dy) noexcept;
569constexpr year_month_weekday
570  operator+(const years& dy, const year_month_weekday& ymwd) noexcept;
571constexpr year_month_weekday
572  operator-(const year_month_weekday& ymwd, const months& dm) noexcept;
573constexpr year_month_weekday
574  operator-(const year_month_weekday& ymwd, const years& dy) noexcept;
575
576template<class charT, class traits>
577  basic_ostream<charT, traits>&
578    operator<<(basic_ostream<charT, traits>& os, const year_month_weekday& ymwd);
579
580// 25.8.17, class year_month_weekday_last    // C++20
581class year_month_weekday_last;
582
583constexpr bool operator==(const year_month_weekday_last& x,
584                          const year_month_weekday_last& y) noexcept;
585constexpr year_month_weekday_last
586  operator+(const year_month_weekday_last& ymwdl, const months& dm) noexcept;
587constexpr year_month_weekday_last
588  operator+(const months& dm, const year_month_weekday_last& ymwdl) noexcept;
589constexpr year_month_weekday_last
590  operator+(const year_month_weekday_last& ymwdl, const years& dy) noexcept;
591constexpr year_month_weekday_last
592  operator+(const years& dy, const year_month_weekday_last& ymwdl) noexcept;
593constexpr year_month_weekday_last
594  operator-(const year_month_weekday_last& ymwdl, const months& dm) noexcept;
595constexpr year_month_weekday_last
596  operator-(const year_month_weekday_last& ymwdl, const years& dy) noexcept;
597
598template<class charT, class traits>
599  basic_ostream<charT, traits>&
600    operator<<(basic_ostream<charT, traits>& os, const year_month_weekday_last& ymwdl);
601
602// 25.8.18, civil calendar conventional syntax operators    // C++20
603constexpr year_month
604  operator/(const year& y, const month& m) noexcept;
605constexpr year_month
606  operator/(const year& y, int m) noexcept;
607constexpr month_day
608  operator/(const month& m, const day& d) noexcept;
609constexpr month_day
610  operator/(const month& m, int d) noexcept;
611constexpr month_day
612  operator/(int m, const day& d) noexcept;
613constexpr month_day
614  operator/(const day& d, const month& m) noexcept;
615constexpr month_day
616  operator/(const day& d, int m) noexcept;
617constexpr month_day_last
618  operator/(const month& m, last_spec) noexcept;
619constexpr month_day_last
620  operator/(int m, last_spec) noexcept;
621constexpr month_day_last
622  operator/(last_spec, const month& m) noexcept;
623constexpr month_day_last
624  operator/(last_spec, int m) noexcept;
625constexpr month_weekday
626  operator/(const month& m, const weekday_indexed& wdi) noexcept;
627constexpr month_weekday
628  operator/(int m, const weekday_indexed& wdi) noexcept;
629constexpr month_weekday
630  operator/(const weekday_indexed& wdi, const month& m) noexcept;
631constexpr month_weekday
632  operator/(const weekday_indexed& wdi, int m) noexcept;
633constexpr month_weekday_last
634  operator/(const month& m, const weekday_last& wdl) noexcept;
635constexpr month_weekday_last
636  operator/(int m, const weekday_last& wdl) noexcept;
637constexpr month_weekday_last
638  operator/(const weekday_last& wdl, const month& m) noexcept;
639constexpr month_weekday_last
640  operator/(const weekday_last& wdl, int m) noexcept;
641constexpr year_month_day
642  operator/(const year_month& ym, const day& d) noexcept;
643constexpr year_month_day
644  operator/(const year_month& ym, int d) noexcept;
645constexpr year_month_day
646  operator/(const year& y, const month_day& md) noexcept;
647constexpr year_month_day
648  operator/(int y, const month_day& md) noexcept;
649constexpr year_month_day
650  operator/(const month_day& md, const year& y) noexcept;
651constexpr year_month_day
652  operator/(const month_day& md, int y) noexcept;
653constexpr year_month_day_last
654  operator/(const year_month& ym, last_spec) noexcept;
655constexpr year_month_day_last
656  operator/(const year& y, const month_day_last& mdl) noexcept;
657constexpr year_month_day_last
658  operator/(int y, const month_day_last& mdl) noexcept;
659constexpr year_month_day_last
660  operator/(const month_day_last& mdl, const year& y) noexcept;
661constexpr year_month_day_last
662  operator/(const month_day_last& mdl, int y) noexcept;
663constexpr year_month_weekday
664  operator/(const year_month& ym, const weekday_indexed& wdi) noexcept;
665constexpr year_month_weekday
666  operator/(const year& y, const month_weekday& mwd) noexcept;
667constexpr year_month_weekday
668  operator/(int y, const month_weekday& mwd) noexcept;
669constexpr year_month_weekday
670  operator/(const month_weekday& mwd, const year& y) noexcept;
671constexpr year_month_weekday
672  operator/(const month_weekday& mwd, int y) noexcept;
673constexpr year_month_weekday_last
674  operator/(const year_month& ym, const weekday_last& wdl) noexcept;
675constexpr year_month_weekday_last
676  operator/(const year& y, const month_weekday_last& mwdl) noexcept;
677constexpr year_month_weekday_last
678  operator/(int y, const month_weekday_last& mwdl) noexcept;
679constexpr year_month_weekday_last
680  operator/(const month_weekday_last& mwdl, const year& y) noexcept;
681constexpr year_month_weekday_last
682  operator/(const month_weekday_last& mwdl, int y) noexcept;
683
684// 26.9, class template hh_mm_ss
685template <class Duration>
686class hh_mm_ss
687{
688    bool            is_neg; // exposition only
689    chrono::hours   h;      // exposition only
690    chrono::minutes m;      // exposition only
691    chrono::seconds s;      // exposition only
692    precision       ss;     // exposition only
693
694public:
695    static unsigned constexpr fractional_width = see below;
696    using precision                            = see below;
697
698    constexpr hh_mm_ss() noexcept : hh_mm_ss{Duration::zero()} {}
699    constexpr explicit hh_mm_ss(Duration d) noexcept;
700
701    constexpr bool is_negative() const noexcept;
702    constexpr chrono::hours hours() const noexcept;
703    constexpr chrono::minutes minutes() const noexcept;
704    constexpr chrono::seconds seconds() const noexcept;
705    constexpr precision subseconds() const noexcept;
706
707    constexpr explicit operator  precision()   const noexcept;
708    constexpr          precision to_duration() const noexcept;
709};
710
711template<class charT, class traits, class Duration>
712  basic_ostream<charT, traits>&
713    operator<<(basic_ostream<charT, traits>& os, const hh_mm_ss<Duration>& hms); // C++20
714
715// 26.10, 12/24 hour functions
716constexpr bool is_am(hours const& h) noexcept;
717constexpr bool is_pm(hours const& h) noexcept;
718constexpr hours make12(const hours& h) noexcept;
719constexpr hours make24(const hours& h, bool is_pm) noexcept;
720
721// [time.zone.db], time zone database
722struct tzdb {                                                                    // C++20
723  string                 version;
724  vector<time_zone>      zones;
725  vector<time_zone_link> links;
726  vector<leap_second>    leap_seconds;
727
728  const time_zone* locate_zone(string_view tz_name) const;
729  const time_zone* current_zone() const;
730};
731
732class tzdb_list {                                                                // C++20
733public:
734  tzdb_list(const tzdb_list&) = delete;
735  tzdb_list& operator=(const tzdb_list&) = delete;
736
737  // unspecified additional constructors
738
739  class const_iterator;
740
741  const tzdb& front() const noexcept;
742
743  const_iterator erase_after(const_iterator p);
744
745  const_iterator begin() const noexcept;
746  const_iterator end()   const noexcept;
747
748  const_iterator cbegin() const noexcept;
749  const_iterator cend()   const noexcept;
750};
751
752// [time.zone.db.access], time zone database access
753const tzdb& get_tzdb();                                                          // C++20
754tzdb_list& get_tzdb_list();                                                      // C++20
755const time_zone* locate_zone(string_view tz_name);                               // C++20
756const time_zone* current_zone()                                                  // C++20
757
758// [time.zone.db.remote], remote time zone database support
759const tzdb& reload_tzdb();                                                       // C++20
760string remote_version();                                                         // C++20
761
762// [time.zone.exception], exception classes
763class nonexistent_local_time;                                                    // C++20
764class ambiguous_local_time;                                                      // C++20
765
766// [time.zone.info], information classes
767struct sys_info {                                                                // C++20
768  sys_seconds   begin;
769  sys_seconds   end;
770  seconds       offset;
771  minutes       save;
772  string        abbrev;
773};
774
775template<class charT, class traits>                                              // C++20
776  basic_ostream<charT, traits>&
777    operator<<(basic_ostream<charT, traits>& os, const sys_info& si);
778
779struct local_info {                                                             // C++20
780  static constexpr int unique      = 0;
781  static constexpr int nonexistent = 1;
782  static constexpr int ambiguous   = 2;
783
784  int result;
785  sys_info first;
786  sys_info second;
787};
788
789template<class charT, class traits>                                              // C++20
790  basic_ostream<charT, traits>&
791    operator<<(basic_ostream<charT, traits>& os, const local_info& li);
792
793// 25.10.5, class time_zone                                                      // C++20
794enum class choose {earliest, latest};
795class time_zone {
796  time_zone(time_zone&&) = default;
797  time_zone& operator=(time_zone&&) = default;
798
799  // unspecified additional constructors
800
801  string_view name() const noexcept;
802
803  template<class Duration>
804  sys_info get_info(const sys_time<Duration>& st) const;
805
806  template<class Duration>
807  local_info get_info(const local_time<Duration>& tp) const;
808
809  template<class Duration>
810  sys_time<common_type_t<Duration, seconds>>
811    to_sys(const local_time<Duration>& tp) const;
812
813  template<class Duration>
814  sys_time<common_type_t<Duration, seconds>>
815    to_sys(const local_time<Duration>& tp, choose z) const;
816
817  template<class Duration>
818  local_time<common_type_t<Duration, seconds>>
819    to_local(const sys_time<Duration>& tp) const;
820};
821bool operator==(const time_zone& x, const time_zone& y) noexcept;                // C++20
822strong_ordering operator<=>(const time_zone& x, const time_zone& y) noexcept;    // C++20
823
824// [time.zone.zonedtraits], class template zoned_traits
825template<class T> struct zoned_traits;                                           // C++20
826
827// [time.zone.zonedtime], class template zoned_time
828template<class Duration, class TimeZonePtr = const time_zone*>                   // C++20
829class zoned_time;
830
831using zoned_seconds = zoned_time<seconds>;                                       // C++20
832
833template<class Duration1, class Duration2, class TimeZonePtr>                    // C++20
834  bool operator==(const zoned_time<Duration1, TimeZonePtr>& x,
835                  const zoned_time<Duration2, TimeZonePtr>& y);
836
837template<class charT, class traits, class Duration, class TimeZonePtr>           // C++20
838  basic_ostream<charT, traits>&
839    operator<<(basic_ostream<charT, traits>& os,
840               const zoned_time<Duration, TimeZonePtr>& t);
841
842// [time.zone.leap], leap second support
843class leap_second {                                                              // C++20
844public:
845  leap_second(const leap_second&)            = default;
846  leap_second& operator=(const leap_second&) = default;
847
848  // unspecified additional constructors
849
850  constexpr sys_seconds date() const noexcept;
851  constexpr seconds value() const noexcept;
852};
853
854constexpr bool operator==(const leap_second& x, const leap_second& y);           // C++20
855constexpr strong_ordering operator<=>(const leap_second& x, const leap_second& y);
856
857template<class Duration>                                                         // C++20
858  constexpr bool operator==(const leap_second& x, const sys_time<Duration>& y);
859template<class Duration>                                                         // C++20
860  constexpr bool operator< (const leap_second& x, const sys_time<Duration>& y);
861template<class Duration>                                                         // C++20
862  constexpr bool operator< (const sys_time<Duration>& x, const leap_second& y);
863template<class Duration>                                                         // C++20
864  constexpr bool operator> (const leap_second& x, const sys_time<Duration>& y);
865template<class Duration>                                                         // C++20
866  constexpr bool operator> (const sys_time<Duration>& x, const leap_second& y);
867template<class Duration>                                                         // C++20
868  constexpr bool operator<=(const leap_second& x, const sys_time<Duration>& y);
869template<class Duration>                                                         // C++20
870  constexpr bool operator<=(const sys_time<Duration>& x, const leap_second& y);
871template<class Duration>                                                         // C++20
872  constexpr bool operator>=(const leap_second& x, const sys_time<Duration>& y);
873template<class Duration>                                                         // C++20
874  constexpr bool operator>=(const sys_time<Duration>& x, const leap_second& y);
875template<class Duration>                                                         // C++20
876  requires three_way_comparable_with<sys_seconds, sys_time<Duration>>
877  constexpr auto operator<=>(const leap_second& x, const sys_time<Duration>& y);
878
879// [time.zone.link], class time_zone_link
880class time_zone_link {                                                           // C++20
881public:
882  time_zone_link(time_zone_link&&)            = default;
883  time_zone_link& operator=(time_zone_link&&) = default;
884
885  // unspecified additional constructors
886
887  string_view name()   const noexcept;
888  string_view target() const noexcept;
889};
890
891bool operator==(const time_zone_link& x, const time_zone_link& y);               // C++20
892strong_ordering operator<=>(const time_zone_link& x, const time_zone_link& y);   // C++20
893
894}  // chrono
895
896namespace std {
897  template<class Duration, class charT>
898    struct formatter<chrono::sys_time<Duration>, charT>;                          // C++20
899  template<class Duration, class charT>
900    struct formatter<chrono::utc_time<Duration>, charT>;                          // C++20
901  template<class Duration, class charT>
902    struct formatter<chrono::filetime<Duration>, charT>;                          // C++20
903  template<class Duration, class charT>
904    struct formatter<chrono::local_time<Duration>, charT>;                        // C++20
905  template<class Rep, class Period, class charT>
906    struct formatter<chrono::duration<Rep, Period>, charT>;                       // C++20
907  template<class charT> struct formatter<chrono::day, charT>;                     // C++20
908  template<class charT> struct formatter<chrono::month, charT>;                   // C++20
909  template<class charT> struct formatter<chrono::year, charT>;                    // C++20
910  template<class charT> struct formatter<chrono::weekday, charT>;                 // C++20
911  template<class charT> struct formatter<chrono::weekday_indexed, charT>;         // C++20
912  template<class charT> struct formatter<chrono::weekday_last, charT>;            // C++20
913  template<class charT> struct formatter<chrono::month_day, charT>;               // C++20
914  template<class charT> struct formatter<chrono::month_day_last, charT>;          // C++20
915  template<class charT> struct formatter<chrono::month_weekday, charT>;           // C++20
916  template<class charT> struct formatter<chrono::month_weekday_last, charT>;      // C++20
917  template<class charT> struct formatter<chrono::year_month, charT>;              // C++20
918  template<class charT> struct formatter<chrono::year_month_day, charT>;          // C++20
919  template<class charT> struct formatter<chrono::year_month_day_last, charT>;     // C++20
920  template<class charT> struct formatter<chrono::year_month_weekday, charT>;      // C++20
921  template<class charT> struct formatter<chrono::year_month_weekday_last, charT>; // C++20
922  template<class Rep, class Period, class charT>
923    struct formatter<chrono::hh_mm_ss<duration<Rep, Period>>, charT>;             // C++20
924  template<class charT> struct formatter<chrono::sys_info, charT>;                // C++20
925  template<class charT> struct formatter<chrono::local_info, charT>;              // C++20
926  template<class Duration, class TimeZonePtr, class charT>                        // C++20
927    struct formatter<chrono::zoned_time<Duration, TimeZonePtr>, charT>;
928} // namespace std
929
930namespace chrono {
931// calendrical constants
932inline constexpr last_spec                              last{};       // C++20
933inline constexpr chrono::weekday                        Sunday{0};    // C++20
934inline constexpr chrono::weekday                        Monday{1};    // C++20
935inline constexpr chrono::weekday                        Tuesday{2};   // C++20
936inline constexpr chrono::weekday                        Wednesday{3}; // C++20
937inline constexpr chrono::weekday                        Thursday{4};  // C++20
938inline constexpr chrono::weekday                        Friday{5};    // C++20
939inline constexpr chrono::weekday                        Saturday{6};  // C++20
940
941inline constexpr chrono::month                          January{1};   // C++20
942inline constexpr chrono::month                          February{2};  // C++20
943inline constexpr chrono::month                          March{3};     // C++20
944inline constexpr chrono::month                          April{4};     // C++20
945inline constexpr chrono::month                          May{5};       // C++20
946inline constexpr chrono::month                          June{6};      // C++20
947inline constexpr chrono::month                          July{7};      // C++20
948inline constexpr chrono::month                          August{8};    // C++20
949inline constexpr chrono::month                          September{9}; // C++20
950inline constexpr chrono::month                          October{10};  // C++20
951inline constexpr chrono::month                          November{11}; // C++20
952inline constexpr chrono::month                          December{12}; // C++20
953}  // chrono
954
955inline namespace literals {
956  inline namespace chrono_literals {
957constexpr chrono::hours                                 operator ""h(unsigned long long); // C++14
958constexpr chrono::duration<unspecified , ratio<3600,1>> operator ""h(long double); // C++14
959constexpr chrono::minutes                               operator ""min(unsigned long long); // C++14
960constexpr chrono::duration<unspecified , ratio<60,1>>   operator ""min(long double); // C++14
961constexpr chrono::seconds                               operator ""s(unsigned long long); // C++14
962constexpr chrono::duration<unspecified >                operator ""s(long double); // C++14
963constexpr chrono::milliseconds                          operator ""ms(unsigned long long); // C++14
964constexpr chrono::duration<unspecified , milli>         operator ""ms(long double); // C++14
965constexpr chrono::microseconds                          operator ""us(unsigned long long); // C++14
966constexpr chrono::duration<unspecified , micro>         operator ""us(long double); // C++14
967constexpr chrono::nanoseconds                           operator ""ns(unsigned long long); // C++14
968constexpr chrono::duration<unspecified , nano>          operator ""ns(long double); // C++14
969constexpr chrono::day                                   operator ""d(unsigned long long d) noexcept; // C++20
970constexpr chrono::year                                  operator ""y(unsigned long long y) noexcept; // C++20
971}  // chrono_literals
972}  // literals
973
974}  // std
975*/
976
977// clang-format on
978
979#if __cplusplus < 201103L && defined(_LIBCPP_USE_FROZEN_CXX03_HEADERS)
980#  include <__cxx03/chrono>
981#else
982#  include <__config>
983
984#  include <__chrono/duration.h>
985#  include <__chrono/file_clock.h>
986#  include <__chrono/high_resolution_clock.h>
987#  include <__chrono/steady_clock.h>
988#  include <__chrono/system_clock.h>
989#  include <__chrono/time_point.h>
990
991#  if _LIBCPP_STD_VER >= 20
992#    include <__chrono/calendar.h>
993#    include <__chrono/day.h>
994#    include <__chrono/exception.h>
995#    include <__chrono/hh_mm_ss.h>
996#    include <__chrono/literals.h>
997#    include <__chrono/local_info.h>
998#    include <__chrono/month.h>
999#    include <__chrono/month_weekday.h>
1000#    include <__chrono/monthday.h>
1001#    include <__chrono/sys_info.h>
1002#    include <__chrono/weekday.h>
1003#    include <__chrono/year.h>
1004#    include <__chrono/year_month.h>
1005#    include <__chrono/year_month_day.h>
1006#    include <__chrono/year_month_weekday.h>
1007
1008#    if _LIBCPP_HAS_LOCALIZATION
1009#      include <__chrono/formatter.h>
1010#      include <__chrono/ostream.h>
1011#      include <__chrono/parser_std_format_spec.h>
1012#      include <__chrono/statically_widen.h>
1013#    endif
1014
1015#    if _LIBCPP_HAS_TIME_ZONE_DATABASE && _LIBCPP_HAS_FILESYSTEM && _LIBCPP_HAS_LOCALIZATION
1016#      include <__chrono/leap_second.h>
1017#      include <__chrono/time_zone.h>
1018#      include <__chrono/time_zone_link.h>
1019#      include <__chrono/tzdb.h>
1020#      include <__chrono/tzdb_list.h>
1021#      include <__chrono/utc_clock.h>
1022#      include <__chrono/zoned_time.h>
1023#    endif
1024
1025#  endif
1026
1027#  include <version>
1028
1029// standard-mandated includes
1030
1031// [time.syn]
1032#  include <compare>
1033
1034#  if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
1035#    pragma GCC system_header
1036#  endif
1037
1038#  if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 17
1039#    include <cstdint>
1040#    include <stdexcept>
1041#    include <string_view>
1042#  endif
1043
1044#  if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
1045#    include <bit>
1046#    include <concepts>
1047#    include <cstring>
1048#    include <forward_list>
1049#    include <string>
1050#    include <tuple>
1051#    include <vector>
1052#  endif
1053
1054#  if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER == 20
1055#    include <charconv>
1056#    if _LIBCPP_HAS_LOCALIZATION
1057#      include <locale>
1058#      include <ostream>
1059#    endif
1060#  endif
1061#endif // __cplusplus < 201103L && defined(_LIBCPP_USE_FROZEN_CXX03_HEADERS)
1062
1063#endif // _LIBCPP_CHRONO
1064