1// chrono::duration and chrono::time_point -*- C++ -*-
2
3// Copyright (C) 2008-2024 Free Software Foundation, Inc.
4//
5// This file is part of the GNU ISO C++ Library. This library is free
6// software; you can redistribute it and/or modify it under the
7// terms of the GNU General Public License as published by the
8// Free Software Foundation; either version 3, or (at your option)
9// any later version.
10
11// This library is distributed in the hope that it will be useful,
12// but WITHOUT ANY WARRANTY; without even the implied warranty of
13// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14// GNU General Public License for more details.
15
16// Under Section 7 of GPL version 3, you are granted additional
17// permissions described in the GCC Runtime Library Exception, version
18// 3.1, as published by the Free Software Foundation.
19
20// You should have received a copy of the GNU General Public License and
21// a copy of the GCC Runtime Library Exception along with this program;
22// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23// <http://www.gnu.org/licenses/>.
24
25/** @file include/bits/chrono.h
26 * This is an internal header file, included by other library headers.
27 * Do not attempt to use it directly. @headername{chrono}
28 */
29
30#ifndef _GLIBCXX_CHRONO_H
31#define _GLIBCXX_CHRONO_H 1
32
33#pragma GCC system_header
34
35#if __cplusplus >= 201103L
36
37#include <ratio>
38#include <type_traits>
39#include <limits>
40#include <ctime>
41#include <bits/parse_numbers.h> // for literals support.
42#if __cplusplus >= 202002L
43# include <concepts>
44# include <compare>
45#endif
46
47#include <bits/version.h>
48
49namespace std _GLIBCXX_VISIBILITY(default)
50{
51_GLIBCXX_BEGIN_NAMESPACE_VERSION
52
53#if __cplusplus >= 201703L
54 namespace filesystem { struct __file_clock; };
55#endif
56
57 namespace chrono
58 {
59 /// @addtogroup chrono
60 /// @{
61
62 /// `chrono::duration` represents a distance between two points in time
63 template<typename _Rep, typename _Period = ratio<1>>
64 class duration;
65
66 /// `chrono::time_point` represents a point in time as measured by a clock
67 template<typename _Clock, typename _Dur = typename _Clock::duration>
68 class time_point;
69 /// @}
70 }
71
72 /// @addtogroup chrono
73 /// @{
74
75 // 20.11.4.3 specialization of common_type (for duration, sfinae-friendly)
76
77 /// @cond undocumented
78
79 template<typename _CT, typename _Period1, typename _Period2, typename = void>
80 struct __duration_common_type
81 { };
82
83 template<typename _CT, typename _Period1, typename _Period2>
84 struct __duration_common_type<_CT, _Period1, _Period2,
85 __void_t<typename _CT::type>>
86 {
87 private:
88 using __gcd_num = __static_gcd<_Period1::num, _Period2::num>;
89 using __gcd_den = __static_gcd<_Period1::den, _Period2::den>;
90 using __cr = typename _CT::type;
91 using __r = ratio<__gcd_num::value,
92 (_Period1::den / __gcd_den::value) * _Period2::den>;
93
94 public:
95 using type = chrono::duration<__cr, typename __r::type>;
96 };
97
98 /// @endcond
99
100 /// @{
101 /// @relates chrono::duration
102
103 /// Specialization of common_type for chrono::duration types.
104 template<typename _Rep1, typename _Period1, typename _Rep2, typename _Period2>
105 struct common_type<chrono::duration<_Rep1, _Period1>,
106 chrono::duration<_Rep2, _Period2>>
107 : __duration_common_type<common_type<_Rep1, _Rep2>,
108 typename _Period1::type,
109 typename _Period2::type>
110 { };
111
112 /// Specialization of common_type for two identical chrono::duration types.
113 template<typename _Rep, typename _Period>
114 struct common_type<chrono::duration<_Rep, _Period>,
115 chrono::duration<_Rep, _Period>>
116 {
117 using type = chrono::duration<typename common_type<_Rep>::type,
118 typename _Period::type>;
119 };
120
121 /// Specialization of common_type for one chrono::duration type.
122 template<typename _Rep, typename _Period>
123 struct common_type<chrono::duration<_Rep, _Period>>
124 {
125 using type = chrono::duration<typename common_type<_Rep>::type,
126 typename _Period::type>;
127 };
128 /// @}
129
130 // 20.11.4.3 specialization of common_type (for time_point, sfinae-friendly)
131
132 /// @cond undocumented
133
134 template<typename _CT, typename _Clock, typename = void>
135 struct __timepoint_common_type
136 { };
137
138 template<typename _CT, typename _Clock>
139 struct __timepoint_common_type<_CT, _Clock, __void_t<typename _CT::type>>
140 {
141 using type = chrono::time_point<_Clock, typename _CT::type>;
142 };
143
144 /// @endcond
145
146 /// @{
147 /// @relates chrono::time_point
148
149 /// Specialization of common_type for chrono::time_point types.
150 template<typename _Clock, typename _Duration1, typename _Duration2>
151 struct common_type<chrono::time_point<_Clock, _Duration1>,
152 chrono::time_point<_Clock, _Duration2>>
153 : __timepoint_common_type<common_type<_Duration1, _Duration2>, _Clock>
154 { };
155
156 /// Specialization of common_type for two identical chrono::time_point types.
157 template<typename _Clock, typename _Duration>
158 struct common_type<chrono::time_point<_Clock, _Duration>,
159 chrono::time_point<_Clock, _Duration>>
160 { using type = chrono::time_point<_Clock, _Duration>; };
161
162 /// Specialization of common_type for one chrono::time_point type.
163 template<typename _Clock, typename _Duration>
164 struct common_type<chrono::time_point<_Clock, _Duration>>
165 { using type = chrono::time_point<_Clock, _Duration>; };
166 /// @}
167
168 /// @} group chrono
169
170 namespace chrono
171 {
172 /// @addtogroup chrono
173 /// @{
174
175 /// @cond undocumented
176
177 // Primary template for duration_cast impl.
178 template<typename _ToDur, typename _CF, typename _CR,
179 bool _NumIsOne = false, bool _DenIsOne = false>
180 struct __duration_cast_impl
181 {
182 template<typename _Rep, typename _Period>
183 static constexpr _ToDur
184 __cast(const duration<_Rep, _Period>& __d)
185 {
186 typedef typename _ToDur::rep __to_rep;
187 return _ToDur(static_cast<__to_rep>(static_cast<_CR>(__d.count())
188 * static_cast<_CR>(_CF::num)
189 / static_cast<_CR>(_CF::den)));
190 }
191 };
192
193 template<typename _ToDur, typename _CF, typename _CR>
194 struct __duration_cast_impl<_ToDur, _CF, _CR, true, true>
195 {
196 template<typename _Rep, typename _Period>
197 static constexpr _ToDur
198 __cast(const duration<_Rep, _Period>& __d)
199 {
200 typedef typename _ToDur::rep __to_rep;
201 return _ToDur(static_cast<__to_rep>(__d.count()));
202 }
203 };
204
205 template<typename _ToDur, typename _CF, typename _CR>
206 struct __duration_cast_impl<_ToDur, _CF, _CR, true, false>
207 {
208 template<typename _Rep, typename _Period>
209 static constexpr _ToDur
210 __cast(const duration<_Rep, _Period>& __d)
211 {
212 typedef typename _ToDur::rep __to_rep;
213 return _ToDur(static_cast<__to_rep>(
214 static_cast<_CR>(__d.count()) / static_cast<_CR>(_CF::den)));
215 }
216 };
217
218 template<typename _ToDur, typename _CF, typename _CR>
219 struct __duration_cast_impl<_ToDur, _CF, _CR, false, true>
220 {
221 template<typename _Rep, typename _Period>
222 static constexpr _ToDur
223 __cast(const duration<_Rep, _Period>& __d)
224 {
225 typedef typename _ToDur::rep __to_rep;
226 return _ToDur(static_cast<__to_rep>(
227 static_cast<_CR>(__d.count()) * static_cast<_CR>(_CF::num)));
228 }
229 };
230
231 template<typename _Tp>
232 struct __is_duration
233 : std::false_type
234 { };
235
236 template<typename _Rep, typename _Period>
237 struct __is_duration<duration<_Rep, _Period>>
238 : std::true_type
239 { };
240
241 template<typename _Tp>
242 using __enable_if_is_duration
243 = typename enable_if<__is_duration<_Tp>::value, _Tp>::type;
244
245 template<typename _Tp>
246 using __disable_if_is_duration
247 = typename enable_if<!__is_duration<_Tp>::value, _Tp>::type;
248
249#if __cplusplus >= 201703L
250 template<typename _Tp>
251 inline constexpr bool __is_duration_v = false;
252 template<typename _Rep, typename _Period>
253 inline constexpr bool __is_duration_v<duration<_Rep, _Period>> = true;
254 template<typename _Tp>
255 inline constexpr bool __is_time_point_v = false;
256 template<typename _Clock, typename _Dur>
257 inline constexpr bool __is_time_point_v<time_point<_Clock, _Dur>> = true;
258#endif
259
260 /// @endcond
261
262 /** Convert a `duration` to type `ToDur`.
263 *
264 * If the duration cannot be represented accurately in the result type,
265 * returns the result of integer truncation (i.e., rounded towards zero).
266 *
267 * @tparam _ToDur The result type must be a `duration`.
268 * @param __d A duration.
269 * @return The value of `__d` converted to type `_ToDur`.
270 * @since C++11
271 */
272 template<typename _ToDur, typename _Rep, typename _Period>
273 _GLIBCXX_NODISCARD
274 constexpr __enable_if_is_duration<_ToDur>
275 duration_cast(const duration<_Rep, _Period>& __d)
276 {
277#if __cpp_inline_variables && __cpp_if_constexpr
278 if constexpr (is_same_v<_ToDur, duration<_Rep, _Period>>)
279 return __d;
280 else
281 {
282#endif
283 using __to_period = typename _ToDur::period;
284 using __to_rep = typename _ToDur::rep;
285 using __cf = ratio_divide<_Period, __to_period>;
286 using __cr = typename common_type<__to_rep, _Rep, intmax_t>::type;
287 using __dc = __duration_cast_impl<_ToDur, __cf, __cr,
288 __cf::num == 1, __cf::den == 1>;
289 return __dc::__cast(__d);
290#if __cpp_inline_variables && __cpp_if_constexpr
291 }
292#endif
293 }
294
295 /** Trait indicating whether to treat a type as a floating-point type.
296 *
297 * The chrono library uses this trait to tell whether a `duration` can
298 * represent fractional values of the given precision, or only integral
299 * values.
300 *
301 * You should specialize this trait for your own numeric types that are
302 * used with `duration` and can represent non-integral values.
303 *
304 * @since C++11
305 */
306 template<typename _Rep>
307 struct treat_as_floating_point
308 : is_floating_point<_Rep>
309 { };
310
311#if __cplusplus > 201402L
312 template <typename _Rep>
313 inline constexpr bool treat_as_floating_point_v =
314 treat_as_floating_point<_Rep>::value;
315
316 template<>
317 inline constexpr bool treat_as_floating_point_v<int> = false;
318 template<>
319 inline constexpr bool treat_as_floating_point_v<long> = false;
320 template<>
321 inline constexpr bool treat_as_floating_point_v<long long> = false;
322 template<>
323 inline constexpr bool treat_as_floating_point_v<float> = true;
324 template<>
325 inline constexpr bool treat_as_floating_point_v<double> = true;
326 template<>
327 inline constexpr bool treat_as_floating_point_v<long double> = true;
328#endif // C++17
329
330#if __cplusplus > 201703L
331#if __cpp_lib_concepts
332 template<typename _Tp>
333 inline constexpr bool is_clock_v = false;
334
335 template<typename _Tp>
336 requires requires {
337 typename _Tp::rep;
338 typename _Tp::period;
339 typename _Tp::duration;
340 typename _Tp::time_point::clock;
341 typename _Tp::time_point::duration;
342 { &_Tp::is_steady } -> same_as<const bool*>;
343 { _Tp::now() } -> same_as<typename _Tp::time_point>;
344 requires same_as<typename _Tp::duration,
345 duration<typename _Tp::rep, typename _Tp::period>>;
346 requires same_as<typename _Tp::time_point::duration,
347 typename _Tp::duration>;
348 }
349 inline constexpr bool is_clock_v<_Tp> = true;
350#else
351 template<typename _Tp, typename = void>
352 inline constexpr bool is_clock_v = false;
353
354 template<typename _Tp>
355 inline constexpr bool
356 is_clock_v<_Tp, void_t<typename _Tp::rep, typename _Tp::period,
357 typename _Tp::duration,
358 typename _Tp::time_point::duration,
359 decltype(_Tp::is_steady),
360 decltype(_Tp::now())>>
361 = __and_v<is_same<typename _Tp::duration,
362 duration<typename _Tp::rep, typename _Tp::period>>,
363 is_same<typename _Tp::time_point::duration,
364 typename _Tp::duration>,
365 is_same<decltype(&_Tp::is_steady), const bool*>,
366 is_same<decltype(_Tp::now()), typename _Tp::time_point>>;
367#endif
368
369 template<typename _Tp>
370 struct is_clock
371 : bool_constant<is_clock_v<_Tp>>
372 { };
373#endif // C++20
374
375#ifdef __glibcxx_chrono // C++ >= 17 && HOSTED
376 /** Convert a `duration` to type `ToDur` and round down.
377 *
378 * If the duration cannot be represented exactly in the result type,
379 * returns the closest value that is less than the argument.
380 *
381 * @tparam _ToDur The result type must be a `duration`.
382 * @param __d A duration.
383 * @return The value of `__d` converted to type `_ToDur`.
384 * @since C++17
385 */
386 template<typename _ToDur, typename _Rep, typename _Period>
387 [[nodiscard]] constexpr __enable_if_is_duration<_ToDur>
388 floor(const duration<_Rep, _Period>& __d)
389 {
390 auto __to = chrono::duration_cast<_ToDur>(__d);
391 if (__to > __d)
392 return __to - _ToDur{1};
393 return __to;
394 }
395
396 /** Convert a `duration` to type `ToDur` and round up.
397 *
398 * If the duration cannot be represented exactly in the result type,
399 * returns the closest value that is greater than the argument.
400 *
401 * @tparam _ToDur The result type must be a `duration`.
402 * @param __d A duration.
403 * @return The value of `__d` converted to type `_ToDur`.
404 * @since C++17
405 */
406 template<typename _ToDur, typename _Rep, typename _Period>
407 [[nodiscard]] constexpr __enable_if_is_duration<_ToDur>
408 ceil(const duration<_Rep, _Period>& __d)
409 {
410 auto __to = chrono::duration_cast<_ToDur>(__d);
411 if (__to < __d)
412 return __to + _ToDur{1};
413 return __to;
414 }
415
416 /** Convert a `duration` to type `ToDur` and round to the closest value.
417 *
418 * If the duration cannot be represented exactly in the result type,
419 * returns the closest value, rounding ties to even.
420 *
421 * @tparam _ToDur The result type must be a `duration` with a
422 * non-floating-point `rep` type.
423 * @param __d A duration.
424 * @return The value of `__d` converted to type `_ToDur`.
425 * @since C++17
426 */
427 template <typename _ToDur, typename _Rep, typename _Period>
428 [[nodiscard]] constexpr
429 enable_if_t<
430 __and_<__is_duration<_ToDur>,
431 __not_<treat_as_floating_point<typename _ToDur::rep>>>::value,
432 _ToDur>
433 round(const duration<_Rep, _Period>& __d)
434 {
435 _ToDur __t0 = chrono::floor<_ToDur>(__d);
436 _ToDur __t1 = __t0 + _ToDur{1};
437 auto __diff0 = __d - __t0;
438 auto __diff1 = __t1 - __d;
439 if (__diff0 == __diff1)
440 {
441 if (__t0.count() & 1)
442 return __t1;
443 return __t0;
444 }
445 else if (__diff0 < __diff1)
446 return __t0;
447 return __t1;
448 }
449
450 /** The absolute (non-negative) value of a duration.
451 *
452 * @param __d A duration with a signed `rep` type.
453 * @return A duration of the same type as the argument, with value |d|.
454 * @since C++17
455 */
456 template<typename _Rep, typename _Period>
457 [[nodiscard]] constexpr
458 enable_if_t<numeric_limits<_Rep>::is_signed, duration<_Rep, _Period>>
459 abs(duration<_Rep, _Period> __d)
460 {
461 if (__d >= __d.zero())
462 return __d;
463 return -__d;
464 }
465
466 // Make chrono::ceil<D> also usable as chrono::__detail::ceil<D>.
467 namespace __detail { using chrono::ceil; }
468
469#else // ! __glibcxx_chrono
470
471 // We want to use ceil even when compiling for earlier standards versions.
472 // C++11 only allows a single statement in a constexpr function, so we
473 // need to move the comparison into a separate function, __ceil_impl.
474 namespace __detail
475 {
476 template<typename _Tp, typename _Up>
477 constexpr _Tp
478 __ceil_impl(const _Tp& __t, const _Up& __u)
479 {
480 return (__t < __u) ? (__t + _Tp{1}) : __t;
481 }
482
483 // C++11-friendly version of std::chrono::ceil<D> for internal use.
484 template<typename _ToDur, typename _Rep, typename _Period>
485 constexpr _ToDur
486 ceil(const duration<_Rep, _Period>& __d)
487 {
488 return __detail::__ceil_impl(chrono::duration_cast<_ToDur>(__d), __d);
489 }
490 }
491#endif // __glibcxx_chrono
492
493 /// duration_values
494 template<typename _Rep>
495 struct duration_values
496 {
497 static constexpr _Rep
498 zero() noexcept
499 { return _Rep(0); }
500
501 static constexpr _Rep
502 max() noexcept
503 { return numeric_limits<_Rep>::max(); }
504
505 static constexpr _Rep
506 min() noexcept
507 { return numeric_limits<_Rep>::lowest(); }
508 };
509
510 template<typename _Rep, typename _Period>
511 class duration
512 {
513 static_assert(!__is_duration<_Rep>::value,
514 "rep cannot be a std::chrono::duration");
515 static_assert(__is_ratio<_Period>::value,
516 "period must be a specialization of std::ratio");
517 static_assert(_Period::num > 0, "period must be positive");
518
519 template<typename _Rep2>
520 using __is_float = treat_as_floating_point<_Rep2>;
521
522 static constexpr intmax_t
523 _S_gcd(intmax_t __m, intmax_t __n) noexcept
524 {
525 // Duration only allows positive periods so we don't need to
526 // handle negative values here (unlike __static_gcd and std::gcd).
527#if __cplusplus >= 201402L
528 do
529 {
530 intmax_t __rem = __m % __n;
531 __m = __n;
532 __n = __rem;
533 }
534 while (__n != 0);
535 return __m;
536#else
537 // C++11 doesn't allow loops in constexpr functions, but this
538 // recursive version can be more expensive to evaluate.
539 return (__n == 0) ? __m : _S_gcd(__n, __m % __n);
540#endif
541 }
542
543 // _GLIBCXX_RESOLVE_LIB_DEFECTS
544 // 2094. overflow shouldn't participate in overload resolution
545 // 3090. What is [2094] intended to mean?
546 // This only produces a valid type if no overflow occurs.
547 template<typename _R1, typename _R2,
548 intmax_t __gcd1 = _S_gcd(m: _R1::num, n: _R2::num),
549 intmax_t __gcd2 = _S_gcd(m: _R1::den, n: _R2::den)>
550 using __divide = ratio<(_R1::num / __gcd1) * (_R2::den / __gcd2),
551 (_R1::den / __gcd2) * (_R2::num / __gcd1)>;
552
553 // _Period2 is an exact multiple of _Period
554 template<typename _Period2>
555 using __is_harmonic
556 = __bool_constant<__divide<_Period2, _Period>::den == 1>;
557
558 public:
559
560 using rep = _Rep;
561 using period = typename _Period::type;
562
563 // 20.11.5.1 construction / copy / destroy
564 constexpr duration() = default;
565
566 duration(const duration&) = default;
567
568 // _GLIBCXX_RESOLVE_LIB_DEFECTS
569 // 3050. Conversion specification problem in chrono::duration
570 template<typename _Rep2, typename = _Require<
571 is_convertible<const _Rep2&, rep>,
572 __or_<__is_float<rep>, __not_<__is_float<_Rep2>>>>>
573 constexpr explicit duration(const _Rep2& __rep)
574 : __r(static_cast<rep>(__rep)) { }
575
576 template<typename _Rep2, typename _Period2, typename = _Require<
577 is_convertible<const _Rep2&, rep>,
578 __or_<__is_float<rep>,
579 __and_<__is_harmonic<_Period2>,
580 __not_<__is_float<_Rep2>>>>>>
581 constexpr duration(const duration<_Rep2, _Period2>& __d)
582 : __r(duration_cast<duration>(__d).count()) { }
583
584 ~duration() = default;
585 duration& operator=(const duration&) = default;
586
587 // 20.11.5.2 observer
588 constexpr rep
589 count() const
590 { return __r; }
591
592 // 20.11.5.3 arithmetic
593
594 constexpr duration<typename common_type<rep>::type, period>
595 operator+() const
596 { return duration<typename common_type<rep>::type, period>(__r); }
597
598 constexpr duration<typename common_type<rep>::type, period>
599 operator-() const
600 { return duration<typename common_type<rep>::type, period>(-__r); }
601
602 _GLIBCXX17_CONSTEXPR duration&
603 operator++()
604 {
605 ++__r;
606 return *this;
607 }
608
609 _GLIBCXX17_CONSTEXPR duration
610 operator++(int)
611 { return duration(__r++); }
612
613 _GLIBCXX17_CONSTEXPR duration&
614 operator--()
615 {
616 --__r;
617 return *this;
618 }
619
620 _GLIBCXX17_CONSTEXPR duration
621 operator--(int)
622 { return duration(__r--); }
623
624 _GLIBCXX17_CONSTEXPR duration&
625 operator+=(const duration& __d)
626 {
627 __r += __d.count();
628 return *this;
629 }
630
631 _GLIBCXX17_CONSTEXPR duration&
632 operator-=(const duration& __d)
633 {
634 __r -= __d.count();
635 return *this;
636 }
637
638 _GLIBCXX17_CONSTEXPR duration&
639 operator*=(const rep& __rhs)
640 {
641 __r *= __rhs;
642 return *this;
643 }
644
645 _GLIBCXX17_CONSTEXPR duration&
646 operator/=(const rep& __rhs)
647 {
648 __r /= __rhs;
649 return *this;
650 }
651
652 // DR 934.
653 template<typename _Rep2 = rep>
654 _GLIBCXX17_CONSTEXPR
655 __enable_if_t<!treat_as_floating_point<_Rep2>::value, duration&>
656 operator%=(const rep& __rhs)
657 {
658 __r %= __rhs;
659 return *this;
660 }
661
662 template<typename _Rep2 = rep>
663 _GLIBCXX17_CONSTEXPR
664 __enable_if_t<!treat_as_floating_point<_Rep2>::value, duration&>
665 operator%=(const duration& __d)
666 {
667 __r %= __d.count();
668 return *this;
669 }
670
671 // 20.11.5.4 special values
672 static constexpr duration
673 zero() noexcept
674 { return duration(duration_values<rep>::zero()); }
675
676 static constexpr duration
677 min() noexcept
678 { return duration(duration_values<rep>::min()); }
679
680 static constexpr duration
681 max() noexcept
682 { return duration(duration_values<rep>::max()); }
683
684 private:
685 rep __r;
686 };
687
688 /// @{
689 /// @relates std::chrono::duration
690
691 /// The sum of two durations.
692 template<typename _Rep1, typename _Period1,
693 typename _Rep2, typename _Period2>
694 constexpr typename common_type<duration<_Rep1, _Period1>,
695 duration<_Rep2, _Period2>>::type
696 operator+(const duration<_Rep1, _Period1>& __lhs,
697 const duration<_Rep2, _Period2>& __rhs)
698 {
699 typedef duration<_Rep1, _Period1> __dur1;
700 typedef duration<_Rep2, _Period2> __dur2;
701 typedef typename common_type<__dur1,__dur2>::type __cd;
702 return __cd(__cd(__lhs).count() + __cd(__rhs).count());
703 }
704
705 /// The difference between two durations.
706 template<typename _Rep1, typename _Period1,
707 typename _Rep2, typename _Period2>
708 constexpr typename common_type<duration<_Rep1, _Period1>,
709 duration<_Rep2, _Period2>>::type
710 operator-(const duration<_Rep1, _Period1>& __lhs,
711 const duration<_Rep2, _Period2>& __rhs)
712 {
713 typedef duration<_Rep1, _Period1> __dur1;
714 typedef duration<_Rep2, _Period2> __dur2;
715 typedef typename common_type<__dur1,__dur2>::type __cd;
716 return __cd(__cd(__lhs).count() - __cd(__rhs).count());
717 }
718
719 /// @}
720
721 /// @cond undocumented
722
723 // SFINAE helper to obtain common_type<_Rep1, _Rep2> only if _Rep2
724 // is implicitly convertible to it.
725 // _GLIBCXX_RESOLVE_LIB_DEFECTS
726 // 3050. Conversion specification problem in chrono::duration constructor
727 template<typename _Rep1, typename _Rep2,
728 typename _CRep = typename common_type<_Rep1, _Rep2>::type>
729 using __common_rep_t = typename
730 enable_if<is_convertible<const _Rep2&, _CRep>::value, _CRep>::type;
731
732 /// @endcond
733
734 /** @{
735 * Arithmetic operators for chrono::duration
736 * @relates std::chrono::duration
737 */
738
739 template<typename _Rep1, typename _Period, typename _Rep2>
740 constexpr duration<__common_rep_t<_Rep1, _Rep2>, _Period>
741 operator*(const duration<_Rep1, _Period>& __d, const _Rep2& __s)
742 {
743 typedef duration<typename common_type<_Rep1, _Rep2>::type, _Period>
744 __cd;
745 return __cd(__cd(__d).count() * __s);
746 }
747
748 template<typename _Rep1, typename _Rep2, typename _Period>
749 constexpr duration<__common_rep_t<_Rep2, _Rep1>, _Period>
750 operator*(const _Rep1& __s, const duration<_Rep2, _Period>& __d)
751 { return __d * __s; }
752
753 template<typename _Rep1, typename _Period, typename _Rep2>
754 constexpr
755 duration<__common_rep_t<_Rep1, __disable_if_is_duration<_Rep2>>, _Period>
756 operator/(const duration<_Rep1, _Period>& __d, const _Rep2& __s)
757 {
758 typedef duration<typename common_type<_Rep1, _Rep2>::type, _Period>
759 __cd;
760 return __cd(__cd(__d).count() / __s);
761 }
762
763 template<typename _Rep1, typename _Period1,
764 typename _Rep2, typename _Period2>
765 constexpr typename common_type<_Rep1, _Rep2>::type
766 operator/(const duration<_Rep1, _Period1>& __lhs,
767 const duration<_Rep2, _Period2>& __rhs)
768 {
769 typedef duration<_Rep1, _Period1> __dur1;
770 typedef duration<_Rep2, _Period2> __dur2;
771 typedef typename common_type<__dur1,__dur2>::type __cd;
772 return __cd(__lhs).count() / __cd(__rhs).count();
773 }
774
775 // DR 934.
776 template<typename _Rep1, typename _Period, typename _Rep2>
777 constexpr
778 duration<__common_rep_t<_Rep1, __disable_if_is_duration<_Rep2>>, _Period>
779 operator%(const duration<_Rep1, _Period>& __d, const _Rep2& __s)
780 {
781 typedef duration<typename common_type<_Rep1, _Rep2>::type, _Period>
782 __cd;
783 return __cd(__cd(__d).count() % __s);
784 }
785
786 template<typename _Rep1, typename _Period1,
787 typename _Rep2, typename _Period2>
788 constexpr typename common_type<duration<_Rep1, _Period1>,
789 duration<_Rep2, _Period2>>::type
790 operator%(const duration<_Rep1, _Period1>& __lhs,
791 const duration<_Rep2, _Period2>& __rhs)
792 {
793 typedef duration<_Rep1, _Period1> __dur1;
794 typedef duration<_Rep2, _Period2> __dur2;
795 typedef typename common_type<__dur1,__dur2>::type __cd;
796 return __cd(__cd(__lhs).count() % __cd(__rhs).count());
797 }
798 /// @}
799
800 // comparisons
801
802 /** @{
803 * Comparisons for chrono::duration
804 * @relates std::chrono::duration
805 */
806
807 template<typename _Rep1, typename _Period1,
808 typename _Rep2, typename _Period2>
809 constexpr bool
810 operator==(const duration<_Rep1, _Period1>& __lhs,
811 const duration<_Rep2, _Period2>& __rhs)
812 {
813 typedef duration<_Rep1, _Period1> __dur1;
814 typedef duration<_Rep2, _Period2> __dur2;
815 typedef typename common_type<__dur1,__dur2>::type __ct;
816 return __ct(__lhs).count() == __ct(__rhs).count();
817 }
818
819 template<typename _Rep1, typename _Period1,
820 typename _Rep2, typename _Period2>
821 constexpr bool
822 operator<(const duration<_Rep1, _Period1>& __lhs,
823 const duration<_Rep2, _Period2>& __rhs)
824 {
825 typedef duration<_Rep1, _Period1> __dur1;
826 typedef duration<_Rep2, _Period2> __dur2;
827 typedef typename common_type<__dur1,__dur2>::type __ct;
828 return __ct(__lhs).count() < __ct(__rhs).count();
829 }
830
831#if __cpp_lib_three_way_comparison
832 template<typename _Rep1, typename _Period1,
833 typename _Rep2, typename _Period2>
834 requires three_way_comparable<common_type_t<_Rep1, _Rep2>>
835 constexpr auto
836 operator<=>(const duration<_Rep1, _Period1>& __lhs,
837 const duration<_Rep2, _Period2>& __rhs)
838 {
839 using __ct = common_type_t<duration<_Rep1, _Period1>,
840 duration<_Rep2, _Period2>>;
841 return __ct(__lhs).count() <=> __ct(__rhs).count();
842 }
843#else
844 template<typename _Rep1, typename _Period1,
845 typename _Rep2, typename _Period2>
846 constexpr bool
847 operator!=(const duration<_Rep1, _Period1>& __lhs,
848 const duration<_Rep2, _Period2>& __rhs)
849 { return !(__lhs == __rhs); }
850#endif
851
852 template<typename _Rep1, typename _Period1,
853 typename _Rep2, typename _Period2>
854 constexpr bool
855 operator<=(const duration<_Rep1, _Period1>& __lhs,
856 const duration<_Rep2, _Period2>& __rhs)
857 { return !(__rhs < __lhs); }
858
859 template<typename _Rep1, typename _Period1,
860 typename _Rep2, typename _Period2>
861 constexpr bool
862 operator>(const duration<_Rep1, _Period1>& __lhs,
863 const duration<_Rep2, _Period2>& __rhs)
864 { return __rhs < __lhs; }
865
866 template<typename _Rep1, typename _Period1,
867 typename _Rep2, typename _Period2>
868 constexpr bool
869 operator>=(const duration<_Rep1, _Period1>& __lhs,
870 const duration<_Rep2, _Period2>& __rhs)
871 { return !(__lhs < __rhs); }
872
873 /// @}
874
875 /// @cond undocumented
876#ifdef _GLIBCXX_USE_C99_STDINT
877# define _GLIBCXX_CHRONO_INT64_T int64_t
878#elif defined __INT64_TYPE__
879# define _GLIBCXX_CHRONO_INT64_T __INT64_TYPE__
880#else
881 static_assert(std::numeric_limits<unsigned long long>::digits >= 64,
882 "Representation type for nanoseconds must have at least 64 bits");
883# define _GLIBCXX_CHRONO_INT64_T long long
884#endif
885 /// @endcond
886
887 /// nanoseconds
888 using nanoseconds = duration<_GLIBCXX_CHRONO_INT64_T, nano>;
889
890 /// microseconds
891 using microseconds = duration<_GLIBCXX_CHRONO_INT64_T, micro>;
892
893 /// milliseconds
894 using milliseconds = duration<_GLIBCXX_CHRONO_INT64_T, milli>;
895
896 /// seconds
897 using seconds = duration<_GLIBCXX_CHRONO_INT64_T>;
898
899 /// minutes
900 using minutes = duration<_GLIBCXX_CHRONO_INT64_T, ratio< 60>>;
901
902 /// hours
903 using hours = duration<_GLIBCXX_CHRONO_INT64_T, ratio<3600>>;
904
905#if __cplusplus > 201703L
906 /// days
907 using days = duration<_GLIBCXX_CHRONO_INT64_T, ratio<86400>>;
908
909 /// weeks
910 using weeks = duration<_GLIBCXX_CHRONO_INT64_T, ratio<604800>>;
911
912 /// years
913 using years = duration<_GLIBCXX_CHRONO_INT64_T, ratio<31556952>>;
914
915 /// months
916 using months = duration<_GLIBCXX_CHRONO_INT64_T, ratio<2629746>>;
917#endif // C++20
918
919#undef _GLIBCXX_CHRONO_INT64_T
920
921 template<typename _Clock, typename _Dur>
922 class time_point
923 {
924 static_assert(__is_duration<_Dur>::value,
925 "duration must be a specialization of std::chrono::duration");
926
927 public:
928 typedef _Clock clock;
929 typedef _Dur duration;
930 typedef typename duration::rep rep;
931 typedef typename duration::period period;
932
933 constexpr time_point() : __d(duration::zero())
934 { }
935
936 constexpr explicit time_point(const duration& __dur)
937 : __d(__dur)
938 { }
939
940 // conversions
941 template<typename _Dur2,
942 typename = _Require<is_convertible<_Dur2, _Dur>>>
943 constexpr time_point(const time_point<clock, _Dur2>& __t)
944 : __d(__t.time_since_epoch())
945 { }
946
947 // observer
948 constexpr duration
949 time_since_epoch() const
950 { return __d; }
951
952#if __cplusplus > 201703L
953 constexpr time_point&
954 operator++()
955 {
956 ++__d;
957 return *this;
958 }
959
960 constexpr time_point
961 operator++(int)
962 { return time_point{__d++}; }
963
964 constexpr time_point&
965 operator--()
966 {
967 --__d;
968 return *this;
969 }
970
971 constexpr time_point
972 operator--(int)
973 { return time_point{__d--}; }
974#endif
975
976 // arithmetic
977 _GLIBCXX17_CONSTEXPR time_point&
978 operator+=(const duration& __dur)
979 {
980 __d += __dur;
981 return *this;
982 }
983
984 _GLIBCXX17_CONSTEXPR time_point&
985 operator-=(const duration& __dur)
986 {
987 __d -= __dur;
988 return *this;
989 }
990
991 // special values
992 static constexpr time_point
993 min() noexcept
994 { return time_point(duration::min()); }
995
996 static constexpr time_point
997 max() noexcept
998 { return time_point(duration::max()); }
999
1000 private:
1001 duration __d;
1002 };
1003
1004 /** Convert a `time_point` to use `duration` type `ToDur`.
1005 *
1006 * The result is the same time point as measured by the same clock, but
1007 * using the specified `duration` to represent the time.
1008 * If the time point cannot be represented accurately in the result type,
1009 * returns the result of integer truncation (i.e., rounded towards zero).
1010 *
1011 * @tparam _ToDur The `duration` type to use for the result.
1012 * @param __t A time point.
1013 * @return The value of `__t` converted to use type `_ToDur`.
1014 * @since C++11
1015 */
1016 template<typename _ToDur, typename _Clock, typename _Dur>
1017 _GLIBCXX_NODISCARD constexpr
1018 __enable_if_t<__is_duration<_ToDur>::value, time_point<_Clock, _ToDur>>
1019 time_point_cast(const time_point<_Clock, _Dur>& __t)
1020 {
1021 typedef time_point<_Clock, _ToDur> __time_point;
1022 return __time_point(duration_cast<_ToDur>(__t.time_since_epoch()));
1023 }
1024
1025#if __cplusplus > 201402L
1026 /** Convert a `time_point` to type `ToDur` and round down.
1027 *
1028 * The result is the same time point as measured by the same clock, but
1029 * using the specified `duration` to represent the time.
1030 * If the time point cannot be represented exactly in the result type,
1031 * returns the closest value that is less than the argument.
1032 *
1033 * @tparam _ToDur The `duration` type to use for the result.
1034 * @param __t A time point.
1035 * @return The value of `__d` converted to type `_ToDur`.
1036 * @since C++17
1037 */
1038 template<typename _ToDur, typename _Clock, typename _Dur>
1039 [[nodiscard]] constexpr
1040 enable_if_t<__is_duration_v<_ToDur>, time_point<_Clock, _ToDur>>
1041 floor(const time_point<_Clock, _Dur>& __tp)
1042 {
1043 return time_point<_Clock, _ToDur>{
1044 chrono::floor<_ToDur>(__tp.time_since_epoch())};
1045 }
1046
1047 /** Convert a `time_point` to type `ToDur` and round up.
1048 *
1049 * The result is the same time point as measured by the same clock, but
1050 * using the specified `duration` to represent the time.
1051 * If the time point cannot be represented exactly in the result type,
1052 * returns the closest value that is greater than the argument.
1053 *
1054 * @tparam _ToDur The `duration` type to use for the result.
1055 * @param __t A time point.
1056 * @return The value of `__d` converted to type `_ToDur`.
1057 * @since C++17
1058 */
1059 template<typename _ToDur, typename _Clock, typename _Dur>
1060 [[nodiscard]] constexpr
1061 enable_if_t<__is_duration_v<_ToDur>, time_point<_Clock, _ToDur>>
1062 ceil(const time_point<_Clock, _Dur>& __tp)
1063 {
1064 return time_point<_Clock, _ToDur>{
1065 chrono::ceil<_ToDur>(__tp.time_since_epoch())};
1066 }
1067
1068 /** Convert a `time_point` to type `ToDur` and round to the closest value.
1069 *
1070 * The result is the same time point as measured by the same clock, but
1071 * using the specified `duration` to represent the time.
1072 * If the time point cannot be represented exactly in the result type,
1073 * returns the closest value, rounding ties to even.
1074 *
1075 * @tparam _ToDur The `duration` type to use for the result,
1076 * which must have a non-floating-point `rep` type.
1077 * @param __t A time point.
1078 * @return The value of `__d` converted to type `_ToDur`.
1079 * @since C++17
1080 */
1081 template<typename _ToDur, typename _Clock, typename _Dur>
1082 [[nodiscard]] constexpr
1083 enable_if_t<__is_duration_v<_ToDur>
1084 && !treat_as_floating_point_v<typename _ToDur::rep>,
1085 time_point<_Clock, _ToDur>>
1086 round(const time_point<_Clock, _Dur>& __tp)
1087 {
1088 return time_point<_Clock, _ToDur>{
1089 chrono::round<_ToDur>(__tp.time_since_epoch())};
1090 }
1091#endif // C++17
1092
1093 /// @{
1094 /// @relates time_point
1095
1096 /// Adjust a time point forwards by the given duration.
1097 template<typename _Clock, typename _Dur1,
1098 typename _Rep2, typename _Period2>
1099 constexpr time_point<_Clock,
1100 typename common_type<_Dur1, duration<_Rep2, _Period2>>::type>
1101 operator+(const time_point<_Clock, _Dur1>& __lhs,
1102 const duration<_Rep2, _Period2>& __rhs)
1103 {
1104 typedef duration<_Rep2, _Period2> __dur2;
1105 typedef typename common_type<_Dur1,__dur2>::type __ct;
1106 typedef time_point<_Clock, __ct> __time_point;
1107 return __time_point(__lhs.time_since_epoch() + __rhs);
1108 }
1109
1110 /// Adjust a time point forwards by the given duration.
1111 template<typename _Rep1, typename _Period1,
1112 typename _Clock, typename _Dur2>
1113 constexpr time_point<_Clock,
1114 typename common_type<duration<_Rep1, _Period1>, _Dur2>::type>
1115 operator+(const duration<_Rep1, _Period1>& __lhs,
1116 const time_point<_Clock, _Dur2>& __rhs)
1117 {
1118 typedef duration<_Rep1, _Period1> __dur1;
1119 typedef typename common_type<__dur1,_Dur2>::type __ct;
1120 typedef time_point<_Clock, __ct> __time_point;
1121 return __time_point(__rhs.time_since_epoch() + __lhs);
1122 }
1123
1124 /// Adjust a time point backwards by the given duration.
1125 template<typename _Clock, typename _Dur1,
1126 typename _Rep2, typename _Period2>
1127 constexpr time_point<_Clock,
1128 typename common_type<_Dur1, duration<_Rep2, _Period2>>::type>
1129 operator-(const time_point<_Clock, _Dur1>& __lhs,
1130 const duration<_Rep2, _Period2>& __rhs)
1131 {
1132 typedef duration<_Rep2, _Period2> __dur2;
1133 typedef typename common_type<_Dur1,__dur2>::type __ct;
1134 typedef time_point<_Clock, __ct> __time_point;
1135 return __time_point(__lhs.time_since_epoch() -__rhs);
1136 }
1137
1138 /// The difference between two time points (as a duration)
1139 template<typename _Clock, typename _Dur1, typename _Dur2>
1140 constexpr typename common_type<_Dur1, _Dur2>::type
1141 operator-(const time_point<_Clock, _Dur1>& __lhs,
1142 const time_point<_Clock, _Dur2>& __rhs)
1143 { return __lhs.time_since_epoch() - __rhs.time_since_epoch(); }
1144 /// @}
1145
1146 /** @{
1147 * Comparisons for time_point
1148 * @relates chrono::time_point
1149 */
1150
1151 template<typename _Clock, typename _Dur1, typename _Dur2>
1152 constexpr bool
1153 operator==(const time_point<_Clock, _Dur1>& __lhs,
1154 const time_point<_Clock, _Dur2>& __rhs)
1155 { return __lhs.time_since_epoch() == __rhs.time_since_epoch(); }
1156
1157#if __cpp_lib_three_way_comparison
1158 template<typename _Clock, typename _Dur1,
1159 three_way_comparable_with<_Dur1> _Dur2>
1160 constexpr auto
1161 operator<=>(const time_point<_Clock, _Dur1>& __lhs,
1162 const time_point<_Clock, _Dur2>& __rhs)
1163 { return __lhs.time_since_epoch() <=> __rhs.time_since_epoch(); }
1164#else
1165 template<typename _Clock, typename _Dur1, typename _Dur2>
1166 constexpr bool
1167 operator!=(const time_point<_Clock, _Dur1>& __lhs,
1168 const time_point<_Clock, _Dur2>& __rhs)
1169 { return !(__lhs == __rhs); }
1170#endif
1171
1172 template<typename _Clock, typename _Dur1, typename _Dur2>
1173 constexpr bool
1174 operator<(const time_point<_Clock, _Dur1>& __lhs,
1175 const time_point<_Clock, _Dur2>& __rhs)
1176 { return __lhs.time_since_epoch() < __rhs.time_since_epoch(); }
1177
1178 template<typename _Clock, typename _Dur1, typename _Dur2>
1179 constexpr bool
1180 operator<=(const time_point<_Clock, _Dur1>& __lhs,
1181 const time_point<_Clock, _Dur2>& __rhs)
1182 { return !(__rhs < __lhs); }
1183
1184 template<typename _Clock, typename _Dur1, typename _Dur2>
1185 constexpr bool
1186 operator>(const time_point<_Clock, _Dur1>& __lhs,
1187 const time_point<_Clock, _Dur2>& __rhs)
1188 { return __rhs < __lhs; }
1189
1190 template<typename _Clock, typename _Dur1, typename _Dur2>
1191 constexpr bool
1192 operator>=(const time_point<_Clock, _Dur1>& __lhs,
1193 const time_point<_Clock, _Dur2>& __rhs)
1194 { return !(__lhs < __rhs); }
1195
1196 /// @}
1197 /// @} group chrono
1198
1199 // Clocks.
1200
1201 // Why nanosecond resolution as the default?
1202 // Why have std::system_clock always count in the highest
1203 // resolution (ie nanoseconds), even if on some OSes the low 3
1204 // or 9 decimal digits will be always zero? This allows later
1205 // implementations to change the system_clock::now()
1206 // implementation any time to provide better resolution without
1207 // changing function signature or units.
1208
1209 // To support the (forward) evolution of the library's defined
1210 // clocks, wrap inside inline namespace so that the current
1211 // defintions of system_clock, steady_clock, and
1212 // high_resolution_clock types are uniquely mangled. This way, new
1213 // code can use the latests clocks, while the library can contain
1214 // compatibility definitions for previous versions. At some
1215 // point, when these clocks settle down, the inlined namespaces
1216 // can be removed. XXX GLIBCXX_ABI Deprecated
1217_GLIBCXX_BEGIN_INLINE_ABI_NAMESPACE(_V2)
1218
1219 /**
1220 * @brief System clock.
1221 *
1222 * Time returned represents wall time from the system-wide clock.
1223 * @ingroup chrono
1224 */
1225 struct system_clock
1226 {
1227 typedef chrono::nanoseconds duration;
1228 typedef duration::rep rep;
1229 typedef duration::period period;
1230 typedef chrono::time_point<system_clock, duration> time_point;
1231
1232 static_assert(system_clock::duration::min()
1233 < system_clock::duration::zero(),
1234 "a clock's minimum duration cannot be less than its epoch");
1235
1236 static constexpr bool is_steady = false;
1237
1238 static time_point
1239 now() noexcept;
1240
1241 // Map to C API
1242 _GLIBCXX_TIME_BITS64_ABI_TAG
1243 static std::time_t
1244 to_time_t(const time_point& __t) noexcept
1245 {
1246 return std::time_t(duration_cast<chrono::seconds>
1247 (d: __t.time_since_epoch()).count());
1248 }
1249
1250 _GLIBCXX_TIME_BITS64_ABI_TAG
1251 static time_point
1252 from_time_t(std::time_t __t) noexcept
1253 {
1254 typedef chrono::time_point<system_clock, seconds> __from;
1255 return time_point_cast<system_clock::duration>
1256 (t: __from(chrono::seconds(__t)));
1257 }
1258 };
1259
1260
1261 /**
1262 * @brief Monotonic clock
1263 *
1264 * Time returned has the property of only increasing at a uniform rate.
1265 * @ingroup chrono
1266 */
1267 struct steady_clock
1268 {
1269 typedef chrono::nanoseconds duration;
1270 typedef duration::rep rep;
1271 typedef duration::period period;
1272 typedef chrono::time_point<steady_clock, duration> time_point;
1273
1274 static constexpr bool is_steady = true;
1275
1276 static time_point
1277 now() noexcept;
1278 };
1279
1280
1281 /**
1282 * @brief Highest-resolution clock
1283 *
1284 * This is the clock "with the shortest tick period." Alias to
1285 * std::system_clock until higher-than-nanosecond definitions
1286 * become feasible.
1287 * @ingroup chrono
1288 */
1289 using high_resolution_clock = system_clock;
1290
1291_GLIBCXX_END_INLINE_ABI_NAMESPACE(_V2)
1292
1293#if __cplusplus >= 202002L
1294 /// @addtogroup chrono
1295 /// @{
1296 template<typename _Duration>
1297 using sys_time = time_point<system_clock, _Duration>;
1298 using sys_seconds = sys_time<seconds>;
1299 using sys_days = sys_time<days>;
1300
1301 using file_clock = ::std::filesystem::__file_clock;
1302
1303 template<typename _Duration>
1304 using file_time = time_point<file_clock, _Duration>;
1305
1306 template<> struct is_clock<system_clock> : true_type { };
1307 template<> struct is_clock<steady_clock> : true_type { };
1308 template<> struct is_clock<file_clock> : true_type { };
1309
1310 template<> inline constexpr bool is_clock_v<system_clock> = true;
1311 template<> inline constexpr bool is_clock_v<steady_clock> = true;
1312 template<> inline constexpr bool is_clock_v<file_clock> = true;
1313 /// @}
1314#endif // C++20
1315 } // namespace chrono
1316
1317#ifdef __glibcxx_chrono_udls // C++ >= 14 && HOSTED
1318 inline namespace literals
1319 {
1320 /** ISO C++ 2014 namespace for suffixes for duration literals.
1321 *
1322 * These suffixes can be used to create `chrono::duration` values with
1323 * tick periods of hours, minutes, seconds, milliseconds, microseconds
1324 * or nanoseconds. For example, `std::chrono::seconds(5)` can be written
1325 * as `5s` after making the suffix visible in the current scope.
1326 * The suffixes can be made visible by a using-directive or
1327 * using-declaration such as:
1328 * - `using namespace std::chrono_literals;`
1329 * - `using namespace std::literals;`
1330 * - `using namespace std::chrono;`
1331 * - `using namespace std;`
1332 * - `using std::chrono_literals::operator""s;`
1333 *
1334 * The result of these suffixes on an integer literal is one of the
1335 * standard typedefs such as `std::chrono::hours`.
1336 * The result on a floating-point literal is a duration type with the
1337 * specified tick period and an unspecified floating-point representation,
1338 * for example `1.5e2ms` might be equivalent to
1339 * `chrono::duration<long double, chrono::milli>(1.5e2)`.
1340 *
1341 * @since C+14
1342 * @ingroup chrono
1343 */
1344 inline namespace chrono_literals
1345 {
1346 /// @addtogroup chrono
1347 /// @{
1348
1349#pragma GCC diagnostic push
1350#pragma GCC diagnostic ignored "-Wliteral-suffix"
1351 /// @cond undocumented
1352 template<typename _Dur, char... _Digits>
1353 constexpr _Dur __check_overflow()
1354 {
1355 using _Val = __parse_int::_Parse_int<_Digits...>;
1356 constexpr typename _Dur::rep __repval = _Val::value;
1357 static_assert(__repval >= 0 && __repval == _Val::value,
1358 "literal value cannot be represented by duration type");
1359 return _Dur(__repval);
1360 }
1361 /// @endcond
1362
1363 /// Literal suffix for durations representing non-integer hours
1364 constexpr chrono::duration<long double, ratio<3600,1>>
1365 operator""h(long double __hours)
1366 { return chrono::duration<long double, ratio<3600,1>>{__hours}; }
1367
1368 /// Literal suffix for durations of type `std::chrono::hours`
1369 template <char... _Digits>
1370 constexpr chrono::hours
1371 operator""h()
1372 { return __check_overflow<chrono::hours, _Digits...>(); }
1373
1374 /// Literal suffix for durations representing non-integer minutes
1375 constexpr chrono::duration<long double, ratio<60,1>>
1376 operator""min(long double __mins)
1377 { return chrono::duration<long double, ratio<60,1>>{__mins}; }
1378
1379 /// Literal suffix for durations of type `std::chrono::minutes`
1380 template <char... _Digits>
1381 constexpr chrono::minutes
1382 operator""min()
1383 { return __check_overflow<chrono::minutes, _Digits...>(); }
1384
1385 /// Literal suffix for durations representing non-integer seconds
1386 constexpr chrono::duration<long double>
1387 operator""s(long double __secs)
1388 { return chrono::duration<long double>{__secs}; }
1389
1390 /// Literal suffix for durations of type `std::chrono::seconds`
1391 template <char... _Digits>
1392 constexpr chrono::seconds
1393 operator""s()
1394 { return __check_overflow<chrono::seconds, _Digits...>(); }
1395
1396 /// Literal suffix for durations representing non-integer milliseconds
1397 constexpr chrono::duration<long double, milli>
1398 operator""ms(long double __msecs)
1399 { return chrono::duration<long double, milli>{__msecs}; }
1400
1401 /// Literal suffix for durations of type `std::chrono::milliseconds`
1402 template <char... _Digits>
1403 constexpr chrono::milliseconds
1404 operator""ms()
1405 { return __check_overflow<chrono::milliseconds, _Digits...>(); }
1406
1407 /// Literal suffix for durations representing non-integer microseconds
1408 constexpr chrono::duration<long double, micro>
1409 operator""us(long double __usecs)
1410 { return chrono::duration<long double, micro>{__usecs}; }
1411
1412 /// Literal suffix for durations of type `std::chrono::microseconds`
1413 template <char... _Digits>
1414 constexpr chrono::microseconds
1415 operator""us()
1416 { return __check_overflow<chrono::microseconds, _Digits...>(); }
1417
1418 /// Literal suffix for durations representing non-integer nanoseconds
1419 constexpr chrono::duration<long double, nano>
1420 operator""ns(long double __nsecs)
1421 { return chrono::duration<long double, nano>{__nsecs}; }
1422
1423 /// Literal suffix for durations of type `std::chrono::nanoseconds`
1424 template <char... _Digits>
1425 constexpr chrono::nanoseconds
1426 operator""ns()
1427 { return __check_overflow<chrono::nanoseconds, _Digits...>(); }
1428
1429#pragma GCC diagnostic pop
1430 /// @}
1431 } // inline namespace chrono_literals
1432 } // inline namespace literals
1433
1434 namespace chrono
1435 {
1436 using namespace literals::chrono_literals;
1437 } // namespace chrono
1438#endif // __glibcxx_chrono_udls
1439
1440#if __cplusplus >= 201703L
1441 namespace filesystem
1442 {
1443 struct __file_clock
1444 {
1445 using duration = chrono::nanoseconds;
1446 using rep = duration::rep;
1447 using period = duration::period;
1448 using time_point = chrono::time_point<__file_clock>;
1449 static constexpr bool is_steady = false;
1450
1451 static time_point
1452 now() noexcept
1453 { return _S_from_sys(t: chrono::system_clock::now()); }
1454
1455#if __cplusplus > 201703L
1456 template<typename _Dur>
1457 static
1458 chrono::file_time<common_type_t<_Dur, chrono::seconds>>
1459 from_sys(const chrono::sys_time<_Dur>& __t) noexcept
1460 { return _S_from_sys(__t); }
1461
1462 // For internal use only
1463 template<typename _Dur>
1464 static
1465 chrono::sys_time<common_type_t<_Dur, chrono::seconds>>
1466 to_sys(const chrono::file_time<_Dur>& __t) noexcept
1467 { return _S_to_sys(__t); }
1468#endif // C++20
1469
1470 private:
1471 using __sys_clock = chrono::system_clock;
1472
1473 // This clock's (unspecified) epoch is 2174-01-01 00:00:00 UTC.
1474 // A signed 64-bit duration with nanosecond resolution gives roughly
1475 // +/- 292 years, which covers the 1901-2446 date range for ext4.
1476 static constexpr chrono::seconds _S_epoch_diff{6437664000};
1477
1478 protected:
1479 // For internal use only
1480 template<typename _Dur>
1481 static
1482 chrono::time_point<__file_clock, common_type_t<_Dur, chrono::seconds>>
1483 _S_from_sys(const chrono::time_point<__sys_clock, _Dur>& __t) noexcept
1484 {
1485 using _CDur = common_type_t<_Dur, chrono::seconds>;
1486 using __file_time = chrono::time_point<__file_clock, _CDur>;
1487 return __file_time{__t.time_since_epoch()} - _S_epoch_diff;
1488 }
1489
1490 // For internal use only
1491 template<typename _Dur>
1492 static
1493 chrono::time_point<__sys_clock, common_type_t<_Dur, chrono::seconds>>
1494 _S_to_sys(const chrono::time_point<__file_clock, _Dur>& __t) noexcept
1495 {
1496 using _CDur = common_type_t<_Dur, chrono::seconds>;
1497 using __sys_time = chrono::time_point<__sys_clock, _CDur>;
1498 return __sys_time{__t.time_since_epoch()} + _S_epoch_diff;
1499 }
1500 };
1501 } // namespace filesystem
1502#endif // C++17
1503
1504_GLIBCXX_END_NAMESPACE_VERSION
1505} // namespace std
1506
1507#endif // C++11
1508
1509#endif //_GLIBCXX_CHRONO_H
1510