1 // chrono::duration and chrono::time_point -*- C++ -*-
2
3 // Copyright (C) 2008-2023 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 namespace std _GLIBCXX_VISIBILITY(default)
48 {
49 _GLIBCXX_BEGIN_NAMESPACE_VERSION
50
51 #if __cplusplus >= 201703L
52 namespace filesystem { struct __file_clock; };
53 #endif
54
55 namespace chrono
56 {
57 /// @addtogroup chrono
58 /// @{
59
60 /// `chrono::duration` represents a distance between two points in time
61 template<typename _Rep, typename _Period = ratio<1>>
62 class duration;
63
64 /// `chrono::time_point` represents a point in time as measured by a clock
65 template<typename _Clock, typename _Dur = typename _Clock::duration>
66 class time_point;
67 /// @}
68 }
69
70 /// @addtogroup chrono
71 /// @{
72
73 // 20.11.4.3 specialization of common_type (for duration, sfinae-friendly)
74
75 /// @cond undocumented
76
77 template<typename _CT, typename _Period1, typename _Period2, typename = void>
78 struct __duration_common_type
79 { };
80
81 template<typename _CT, typename _Period1, typename _Period2>
82 struct __duration_common_type<_CT, _Period1, _Period2,
83 __void_t<typename _CT::type>>
84 {
85 private:
86 using __gcd_num = __static_gcd<_Period1::num, _Period2::num>;
87 using __gcd_den = __static_gcd<_Period1::den, _Period2::den>;
88 using __cr = typename _CT::type;
89 using __r = ratio<__gcd_num::value,
90 (_Period1::den / __gcd_den::value) * _Period2::den>;
91
92 public:
93 using type = chrono::duration<__cr, typename __r::type>;
94 };
95
96 /// @endcond
97
98 /// @{
99 /// @relates chrono::duration
100
101 /// Specialization of common_type for chrono::duration types.
102 template<typename _Rep1, typename _Period1, typename _Rep2, typename _Period2>
103 struct common_type<chrono::duration<_Rep1, _Period1>,
104 chrono::duration<_Rep2, _Period2>>
105 : __duration_common_type<common_type<_Rep1, _Rep2>,
106 typename _Period1::type,
107 typename _Period2::type>
108 { };
109
110 /// Specialization of common_type for two identical chrono::duration types.
111 template<typename _Rep, typename _Period>
112 struct common_type<chrono::duration<_Rep, _Period>,
113 chrono::duration<_Rep, _Period>>
114 {
115 using type = chrono::duration<typename common_type<_Rep>::type,
116 typename _Period::type>;
117 };
118
119 /// Specialization of common_type for one chrono::duration type.
120 template<typename _Rep, typename _Period>
121 struct common_type<chrono::duration<_Rep, _Period>>
122 {
123 using type = chrono::duration<typename common_type<_Rep>::type,
124 typename _Period::type>;
125 };
126 /// @}
127
128 // 20.11.4.3 specialization of common_type (for time_point, sfinae-friendly)
129
130 /// @cond undocumented
131
132 template<typename _CT, typename _Clock, typename = void>
133 struct __timepoint_common_type
134 { };
135
136 template<typename _CT, typename _Clock>
137 struct __timepoint_common_type<_CT, _Clock, __void_t<typename _CT::type>>
138 {
139 using type = chrono::time_point<_Clock, typename _CT::type>;
140 };
141
142 /// @endcond
143
144 /// @{
145 /// @relates chrono::time_point
146
147 /// Specialization of common_type for chrono::time_point types.
148 template<typename _Clock, typename _Duration1, typename _Duration2>
149 struct common_type<chrono::time_point<_Clock, _Duration1>,
150 chrono::time_point<_Clock, _Duration2>>
151 : __timepoint_common_type<common_type<_Duration1, _Duration2>, _Clock>
152 { };
153
154 /// Specialization of common_type for two identical chrono::time_point types.
155 template<typename _Clock, typename _Duration>
156 struct common_type<chrono::time_point<_Clock, _Duration>,
157 chrono::time_point<_Clock, _Duration>>
158 { using type = chrono::time_point<_Clock, _Duration>; };
159
160 /// Specialization of common_type for one chrono::time_point type.
161 template<typename _Clock, typename _Duration>
162 struct common_type<chrono::time_point<_Clock, _Duration>>
163 { using type = chrono::time_point<_Clock, _Duration>; };
164 /// @}
165
166 /// @} group chrono
167
168 namespace chrono
169 {
170 /// @addtogroup chrono
171 /// @{
172
173 /// @cond undocumented
174
175 // Primary template for duration_cast impl.
176 template<typename _ToDur, typename _CF, typename _CR,
177 bool _NumIsOne = false, bool _DenIsOne = false>
178 struct __duration_cast_impl
179 {
180 template<typename _Rep, typename _Period>
181 static constexpr _ToDur
182 __cast(const duration<_Rep, _Period>& __d)
183 {
184 typedef typename _ToDur::rep __to_rep;
185 return _ToDur(static_cast<__to_rep>(static_cast<_CR>(__d.count())
186 * static_cast<_CR>(_CF::num)
187 / static_cast<_CR>(_CF::den)));
188 }
189 };
190
191 template<typename _ToDur, typename _CF, typename _CR>
192 struct __duration_cast_impl<_ToDur, _CF, _CR, true, true>
193 {
194 template<typename _Rep, typename _Period>
195 static constexpr _ToDur
196 __cast(const duration<_Rep, _Period>& __d)
197 {
198 typedef typename _ToDur::rep __to_rep;
199 return _ToDur(static_cast<__to_rep>(__d.count()));
200 }
201 };
202
203 template<typename _ToDur, typename _CF, typename _CR>
204 struct __duration_cast_impl<_ToDur, _CF, _CR, true, false>
205 {
206 template<typename _Rep, typename _Period>
207 static constexpr _ToDur
208 __cast(const duration<_Rep, _Period>& __d)
209 {
210 typedef typename _ToDur::rep __to_rep;
211 return _ToDur(static_cast<__to_rep>(
212 static_cast<_CR>(__d.count()) / static_cast<_CR>(_CF::den)));
213 }
214 };
215
216 template<typename _ToDur, typename _CF, typename _CR>
217 struct __duration_cast_impl<_ToDur, _CF, _CR, false, true>
218 {
219 template<typename _Rep, typename _Period>
220 static constexpr _ToDur
221 __cast(const duration<_Rep, _Period>& __d)
222 {
223 typedef typename _ToDur::rep __to_rep;
224 return _ToDur(static_cast<__to_rep>(
225 static_cast<_CR>(__d.count()) * static_cast<_CR>(_CF::num)));
226 }
227 };
228
229 template<typename _Tp>
230 struct __is_duration
231 : std::false_type
232 { };
233
234 template<typename _Rep, typename _Period>
235 struct __is_duration<duration<_Rep, _Period>>
236 : std::true_type
237 { };
238
239 template<typename _Tp>
240 using __enable_if_is_duration
241 = typename enable_if<__is_duration<_Tp>::value, _Tp>::type;
242
243 template<typename _Tp>
244 using __disable_if_is_duration
245 = typename enable_if<!__is_duration<_Tp>::value, _Tp>::type;
246
247 #if __cplusplus >= 201703L
248 template<typename _Tp>
249 inline constexpr bool __is_duration_v = false;
250 template<typename _Rep, typename _Period>
251 inline constexpr bool __is_duration_v<duration<_Rep, _Period>> = true;
252 template<typename _Tp>
253 inline constexpr bool __is_time_point_v = false;
254 template<typename _Clock, typename _Dur>
255 inline constexpr bool __is_time_point_v<time_point<_Clock, _Dur>> = true;
256 #endif
257
258 /// @endcond
259
260 /** Convert a `duration` to type `ToDur`.
261 *
262 * If the duration cannot be represented accurately in the result type,
263 * returns the result of integer truncation (i.e., rounded towards zero).
264 *
265 * @tparam _ToDur The result type must be a `duration`.
266 * @param __d A duration.
267 * @return The value of `__d` converted to type `_ToDur`.
268 * @since C++11
269 */
270 template<typename _ToDur, typename _Rep, typename _Period>
271 _GLIBCXX_NODISCARD
272 constexpr __enable_if_is_duration<_ToDur>
273 duration_cast(const duration<_Rep, _Period>& __d)
274 {
275 #if __cpp_inline_variables && __cpp_if_constexpr
276 if constexpr (is_same_v<_ToDur, duration<_Rep, _Period>>)
277 return __d;
278 else
279 #endif
280 {
281 using __to_period = typename _ToDur::period;
282 using __to_rep = typename _ToDur::rep;
283 using __cf = ratio_divide<_Period, __to_period>;
284 using __cr = typename common_type<__to_rep, _Rep, intmax_t>::type;
285 using __dc = __duration_cast_impl<_ToDur, __cf, __cr,
286 __cf::num == 1, __cf::den == 1>;
287 return __dc::__cast(__d);
288 }
289 }
290
291 /** Trait indicating whether to treat a type as a floating-point type.
292 *
293 * The chrono library uses this trait to tell whether a `duration` can
294 * represent fractional values of the given precision, or only integral
295 * values.
296 *
297 * You should specialize this trait for your own numeric types that are
298 * used with `duration` and can represent non-integral values.
299 *
300 * @since C++11
301 */
302 template<typename _Rep>
303 struct treat_as_floating_point
304 : is_floating_point<_Rep>
305 { };
306
307 #if __cplusplus > 201402L
308 template <typename _Rep>
309 inline constexpr bool treat_as_floating_point_v =
310 treat_as_floating_point<_Rep>::value;
311
312 template<>
313 inline constexpr bool treat_as_floating_point_v<int> = false;
314 template<>
315 inline constexpr bool treat_as_floating_point_v<long> = false;
316 template<>
317 inline constexpr bool treat_as_floating_point_v<long long> = false;
318 template<>
319 inline constexpr bool treat_as_floating_point_v<float> = true;
320 template<>
321 inline constexpr bool treat_as_floating_point_v<double> = true;
322 template<>
323 inline constexpr bool treat_as_floating_point_v<long double> = true;
324 #endif // C++17
325
326 #if __cplusplus > 201703L
327 #if __cpp_lib_concepts
328 template<typename _Tp>
329 inline constexpr bool is_clock_v = false;
330
331 template<typename _Tp>
332 requires requires {
333 typename _Tp::rep;
334 typename _Tp::period;
335 typename _Tp::duration;
336 typename _Tp::time_point::clock;
337 typename _Tp::time_point::duration;
338 { &_Tp::is_steady } -> same_as<const bool*>;
339 { _Tp::now() } -> same_as<typename _Tp::time_point>;
340 requires same_as<typename _Tp::duration,
341 duration<typename _Tp::rep, typename _Tp::period>>;
342 requires same_as<typename _Tp::time_point::duration,
343 typename _Tp::duration>;
344 }
345 inline constexpr bool is_clock_v<_Tp> = true;
346 #else
347 template<typename _Tp, typename = void>
348 inline constexpr bool is_clock_v = false;
349
350 template<typename _Tp>
351 inline constexpr bool
352 is_clock_v<_Tp, void_t<typename _Tp::rep, typename _Tp::period,
353 typename _Tp::duration,
354 typename _Tp::time_point::duration,
355 decltype(_Tp::is_steady),
356 decltype(_Tp::now())>>
357 = __and_v<is_same<typename _Tp::duration,
358 duration<typename _Tp::rep, typename _Tp::period>>,
359 is_same<typename _Tp::time_point::duration,
360 typename _Tp::duration>,
361 is_same<decltype(&_Tp::is_steady), const bool*>,
362 is_same<decltype(_Tp::now()), typename _Tp::time_point>>;
363 #endif
364
365 template<typename _Tp>
366 struct is_clock
367 : bool_constant<is_clock_v<_Tp>>
368 { };
369 #endif // C++20
370
371 #if __cplusplus >= 201703L
372 # define __cpp_lib_chrono 201611L
373
374 /** Convert a `duration` to type `ToDur` and round down.
375 *
376 * If the duration cannot be represented exactly in the result type,
377 * returns the closest value that is less than the argument.
378 *
379 * @tparam _ToDur The result type must be a `duration`.
380 * @param __d A duration.
381 * @return The value of `__d` converted to type `_ToDur`.
382 * @since C++17
383 */
384 template<typename _ToDur, typename _Rep, typename _Period>
385 [[nodiscard]] constexpr __enable_if_is_duration<_ToDur>
386 floor(const duration<_Rep, _Period>& __d)
387 {
388 auto __to = chrono::duration_cast<_ToDur>(__d);
389 if (__to > __d)
390 return __to - _ToDur{1};
391 return __to;
392 }
393
394 /** Convert a `duration` to type `ToDur` and round up.
395 *
396 * If the duration cannot be represented exactly in the result type,
397 * returns the closest value that is greater than the argument.
398 *
399 * @tparam _ToDur The result type must be a `duration`.
400 * @param __d A duration.
401 * @return The value of `__d` converted to type `_ToDur`.
402 * @since C++17
403 */
404 template<typename _ToDur, typename _Rep, typename _Period>
405 [[nodiscard]] constexpr __enable_if_is_duration<_ToDur>
406 ceil(const duration<_Rep, _Period>& __d)
407 {
408 auto __to = chrono::duration_cast<_ToDur>(__d);
409 if (__to < __d)
410 return __to + _ToDur{1};
411 return __to;
412 }
413
414 /** Convert a `duration` to type `ToDur` and round to the closest value.
415 *
416 * If the duration cannot be represented exactly in the result type,
417 * returns the closest value, rounding ties to even.
418 *
419 * @tparam _ToDur The result type must be a `duration` with a
420 * non-floating-point `rep` type.
421 * @param __d A duration.
422 * @return The value of `__d` converted to type `_ToDur`.
423 * @since C++17
424 */
425 template <typename _ToDur, typename _Rep, typename _Period>
426 [[nodiscard]] constexpr
427 enable_if_t<
428 __and_<__is_duration<_ToDur>,
429 __not_<treat_as_floating_point<typename _ToDur::rep>>>::value,
430 _ToDur>
431 round(const duration<_Rep, _Period>& __d)
432 {
433 _ToDur __t0 = chrono::floor<_ToDur>(__d);
434 _ToDur __t1 = __t0 + _ToDur{1};
435 auto __diff0 = __d - __t0;
436 auto __diff1 = __t1 - __d;
437 if (__diff0 == __diff1)
438 {
439 if (__t0.count() & 1)
440 return __t1;
441 return __t0;
442 }
443 else if (__diff0 < __diff1)
444 return __t0;
445 return __t1;
446 }
447
448 /** The absolute (non-negative) value of a duration.
449 *
450 * @param __d A duration with a signed `rep` type.
451 * @return A duration of the same type as the argument, with value |d|.
452 * @since C++17
453 */
454 template<typename _Rep, typename _Period>
455 [[nodiscard]] constexpr
456 enable_if_t<numeric_limits<_Rep>::is_signed, duration<_Rep, _Period>>
457 abs(duration<_Rep, _Period> __d)
458 {
459 if (__d >= __d.zero())
460 return __d;
461 return -__d;
462 }
463
464 // Make chrono::ceil<D> also usable as chrono::__detail::ceil<D>.
465 namespace __detail { using chrono::ceil; }
466
467 #else // ! C++17
468
469 // We want to use ceil even when compiling for earlier standards versions.
470 // C++11 only allows a single statement in a constexpr function, so we
471 // need to move the comparison into a separate function, __ceil_impl.
472 namespace __detail
473 {
474 template<typename _Tp, typename _Up>
475 constexpr _Tp
476 __ceil_impl(const _Tp& __t, const _Up& __u)
477 {
478 return (__t < __u) ? (__t + _Tp{1}) : __t;
479 }
480
481 // C++11-friendly version of std::chrono::ceil<D> for internal use.
482 template<typename _ToDur, typename _Rep, typename _Period>
483 constexpr _ToDur
484 ceil(const duration<_Rep, _Period>& __d)
485 {
486 return __detail::__ceil_impl(chrono::duration_cast<_ToDur>(__d), __d);
487 }
488 }
489 #endif // C++17
490
491 /// duration_values
492 template<typename _Rep>
493 struct duration_values
494 {
495 static constexpr _Rep
496 zero() noexcept
497 { return _Rep(0); }
498
499 static constexpr _Rep
500 max() noexcept
501 { return numeric_limits<_Rep>::max(); }
502
503 static constexpr _Rep
504 min() noexcept
505 { return numeric_limits<_Rep>::lowest(); }
506 };
507
508 /// @cond undocumented
509
510 template<typename _Tp>
511 struct __is_ratio
512 : std::false_type
513 { };
514
515 template<intmax_t _Num, intmax_t _Den>
516 struct __is_ratio<ratio<_Num, _Den>>
517 : std::true_type
518 { };
519
520 /// @endcond
521
522 template<typename _Rep, typename _Period>
523 class duration
524 {
525 static_assert(!__is_duration<_Rep>::value, "rep cannot be a duration");
526 static_assert(__is_ratio<_Period>::value,
527 "period must be a specialization of ratio");
528 static_assert(_Period::num > 0, "period must be positive");
529
530 template<typename _Rep2>
531 using __is_float = treat_as_floating_point<_Rep2>;
532
533 static constexpr intmax_t
534 _S_gcd(intmax_t __m, intmax_t __n) noexcept
535 {
536 // Duration only allows positive periods so we don't need to
537 // handle negative values here (unlike __static_gcd and std::gcd).
538 #if __cplusplus >= 201402L
539 do
540 {
541 intmax_t __rem = __m % __n;
542 __m = __n;
543 __n = __rem;
544 }
545 while (__n != 0);
546 return __m;
547 #else
548 // C++11 doesn't allow loops in constexpr functions, but this
549 // recursive version can be more expensive to evaluate.
550 return (__n == 0) ? __m : _S_gcd(__n, __m % __n);
551 #endif
552 }
553
554 // _GLIBCXX_RESOLVE_LIB_DEFECTS
555 // 2094. overflow shouldn't participate in overload resolution
556 // 3090. What is [2094] intended to mean?
557 // This only produces a valid type if no overflow occurs.
558 template<typename _R1, typename _R2,
559 intmax_t __gcd1 = _S_gcd(_R1::num, _R2::num),
560 intmax_t __gcd2 = _S_gcd(_R1::den, _R2::den)>
561 using __divide = ratio<(_R1::num / __gcd1) * (_R2::den / __gcd2),
562 (_R1::den / __gcd2) * (_R2::num / __gcd1)>;
563
564 // _Period2 is an exact multiple of _Period
565 template<typename _Period2>
566 using __is_harmonic
567 = __bool_constant<__divide<_Period2, _Period>::den == 1>;
568
569 public:
570
571 using rep = _Rep;
572 using period = typename _Period::type;
573
574 // 20.11.5.1 construction / copy / destroy
575 constexpr duration() = default;
576
577 duration(const duration&) = default;
578
579 // _GLIBCXX_RESOLVE_LIB_DEFECTS
580 // 3050. Conversion specification problem in chrono::duration
581 template<typename _Rep2, typename = _Require<
582 is_convertible<const _Rep2&, rep>,
583 __or_<__is_float<rep>, __not_<__is_float<_Rep2>>>>>
584 constexpr explicit duration(const _Rep2& __rep)
585 : __r(static_cast<rep>(__rep)) { }
586
587 template<typename _Rep2, typename _Period2, typename = _Require<
588 is_convertible<const _Rep2&, rep>,
589 __or_<__is_float<rep>,
590 __and_<__is_harmonic<_Period2>,
591 __not_<__is_float<_Rep2>>>>>>
592 constexpr duration(const duration<_Rep2, _Period2>& __d)
593 : __r(duration_cast<duration>(__d).count()) { }
594
595 ~duration() = default;
596 duration& operator=(const duration&) = default;
597
598 // 20.11.5.2 observer
599 constexpr rep
600 count() const
601 { return __r; }
602
603 // 20.11.5.3 arithmetic
604
605 constexpr duration<typename common_type<rep>::type, period>
606 operator+() const
607 { return duration<typename common_type<rep>::type, period>(__r); }
608
609 constexpr duration<typename common_type<rep>::type, period>
610 operator-() const
611 { return duration<typename common_type<rep>::type, period>(-__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--()
626 {
627 --__r;
628 return *this;
629 }
630
631 _GLIBCXX17_CONSTEXPR duration
632 operator--(int)
633 { return duration(__r--); }
634
635 _GLIBCXX17_CONSTEXPR duration&
636 operator+=(const duration& __d)
637 {
638 __r += __d.count();
639 return *this;
640 }
641
642 _GLIBCXX17_CONSTEXPR duration&
643 operator-=(const duration& __d)
644 {
645 __r -= __d.count();
646 return *this;
647 }
648
649 _GLIBCXX17_CONSTEXPR duration&
650 operator*=(const rep& __rhs)
651 {
652 __r *= __rhs;
653 return *this;
654 }
655
656 _GLIBCXX17_CONSTEXPR duration&
657 operator/=(const rep& __rhs)
658 {
659 __r /= __rhs;
660 return *this;
661 }
662
663 // DR 934.
664 template<typename _Rep2 = rep>
665 _GLIBCXX17_CONSTEXPR
666 __enable_if_t<!treat_as_floating_point<_Rep2>::value, duration&>
667 operator%=(const rep& __rhs)
668 {
669 __r %= __rhs;
670 return *this;
671 }
672
673 template<typename _Rep2 = rep>
674 _GLIBCXX17_CONSTEXPR
675 __enable_if_t<!treat_as_floating_point<_Rep2>::value, duration&>
676 operator%=(const duration& __d)
677 {
678 __r %= __d.count();
679 return *this;
680 }
681
682 // 20.11.5.4 special values
683 static constexpr duration
684 zero() noexcept
685 { return duration(duration_values<rep>::zero()); }
686
687 static constexpr duration
688 min() noexcept
689 { return duration(duration_values<rep>::min()); }
690
691 static constexpr duration
692 max() noexcept
693 { return duration(duration_values<rep>::max()); }
694
695 private:
696 rep __r;
697 };
698
699 /// @{
700 /// @relates std::chrono::duration
701
702 /// The sum of two durations.
703 template<typename _Rep1, typename _Period1,
704 typename _Rep2, typename _Period2>
705 constexpr typename common_type<duration<_Rep1, _Period1>,
706 duration<_Rep2, _Period2>>::type
707 operator+(const duration<_Rep1, _Period1>& __lhs,
708 const duration<_Rep2, _Period2>& __rhs)
709 {
710 typedef duration<_Rep1, _Period1> __dur1;
711 typedef duration<_Rep2, _Period2> __dur2;
712 typedef typename common_type<__dur1,__dur2>::type __cd;
713 return __cd(__cd(__lhs).count() + __cd(__rhs).count());
714 }
715
716 /// The difference between two durations.
717 template<typename _Rep1, typename _Period1,
718 typename _Rep2, typename _Period2>
719 constexpr typename common_type<duration<_Rep1, _Period1>,
720 duration<_Rep2, _Period2>>::type
721 operator-(const duration<_Rep1, _Period1>& __lhs,
722 const duration<_Rep2, _Period2>& __rhs)
723 {
724 typedef duration<_Rep1, _Period1> __dur1;
725 typedef duration<_Rep2, _Period2> __dur2;
726 typedef typename common_type<__dur1,__dur2>::type __cd;
727 return __cd(__cd(__lhs).count() - __cd(__rhs).count());
728 }
729
730 /// @}
731
732 /// @cond undocumented
733
734 // SFINAE helper to obtain common_type<_Rep1, _Rep2> only if _Rep2
735 // is implicitly convertible to it.
736 // _GLIBCXX_RESOLVE_LIB_DEFECTS
737 // 3050. Conversion specification problem in chrono::duration constructor
738 template<typename _Rep1, typename _Rep2,
739 typename _CRep = typename common_type<_Rep1, _Rep2>::type>
740 using __common_rep_t = typename
741 enable_if<is_convertible<const _Rep2&, _CRep>::value, _CRep>::type;
742
743 /// @endcond
744
745 /** @{
746 * Arithmetic operators for chrono::duration
747 * @relates std::chrono::duration
748 */
749
750 template<typename _Rep1, typename _Period, typename _Rep2>
751 constexpr duration<__common_rep_t<_Rep1, _Rep2>, _Period>
752 operator*(const duration<_Rep1, _Period>& __d, const _Rep2& __s)
753 {
754 typedef duration<typename common_type<_Rep1, _Rep2>::type, _Period>
755 __cd;
756 return __cd(__cd(__d).count() * __s);
757 }
758
759 template<typename _Rep1, typename _Rep2, typename _Period>
760 constexpr duration<__common_rep_t<_Rep2, _Rep1>, _Period>
761 operator*(const _Rep1& __s, const duration<_Rep2, _Period>& __d)
762 { return __d * __s; }
763
764 template<typename _Rep1, typename _Period, typename _Rep2>
765 constexpr
766 duration<__common_rep_t<_Rep1, __disable_if_is_duration<_Rep2>>, _Period>
767 operator/(const duration<_Rep1, _Period>& __d, const _Rep2& __s)
768 {
769 typedef duration<typename common_type<_Rep1, _Rep2>::type, _Period>
770 __cd;
771 return __cd(__cd(__d).count() / __s);
772 }
773
774 template<typename _Rep1, typename _Period1,
775 typename _Rep2, typename _Period2>
776 constexpr typename common_type<_Rep1, _Rep2>::type
777 operator/(const duration<_Rep1, _Period1>& __lhs,
778 const duration<_Rep2, _Period2>& __rhs)
779 {
780 typedef duration<_Rep1, _Period1> __dur1;
781 typedef duration<_Rep2, _Period2> __dur2;
782 typedef typename common_type<__dur1,__dur2>::type __cd;
783 return __cd(__lhs).count() / __cd(__rhs).count();
784 }
785
786 // DR 934.
787 template<typename _Rep1, typename _Period, typename _Rep2>
788 constexpr
789 duration<__common_rep_t<_Rep1, __disable_if_is_duration<_Rep2>>, _Period>
790 operator%(const duration<_Rep1, _Period>& __d, const _Rep2& __s)
791 {
792 typedef duration<typename common_type<_Rep1, _Rep2>::type, _Period>
793 __cd;
794 return __cd(__cd(__d).count() % __s);
795 }
796
797 template<typename _Rep1, typename _Period1,
798 typename _Rep2, typename _Period2>
799 constexpr typename common_type<duration<_Rep1, _Period1>,
800 duration<_Rep2, _Period2>>::type
801 operator%(const duration<_Rep1, _Period1>& __lhs,
802 const duration<_Rep2, _Period2>& __rhs)
803 {
804 typedef duration<_Rep1, _Period1> __dur1;
805 typedef duration<_Rep2, _Period2> __dur2;
806 typedef typename common_type<__dur1,__dur2>::type __cd;
807 return __cd(__cd(__lhs).count() % __cd(__rhs).count());
808 }
809 /// @}
810
811 // comparisons
812
813 /** @{
814 * Comparisons for chrono::duration
815 * @relates std::chrono::duration
816 */
817
818 template<typename _Rep1, typename _Period1,
819 typename _Rep2, typename _Period2>
820 constexpr bool
821 operator==(const duration<_Rep1, _Period1>& __lhs,
822 const duration<_Rep2, _Period2>& __rhs)
823 {
824 typedef duration<_Rep1, _Period1> __dur1;
825 typedef duration<_Rep2, _Period2> __dur2;
826 typedef typename common_type<__dur1,__dur2>::type __ct;
827 return __ct(__lhs).count() == __ct(__rhs).count();
828 }
829
830 template<typename _Rep1, typename _Period1,
831 typename _Rep2, typename _Period2>
832 constexpr bool
833 operator<(const duration<_Rep1, _Period1>& __lhs,
834 const duration<_Rep2, _Period2>& __rhs)
835 {
836 typedef duration<_Rep1, _Period1> __dur1;
837 typedef duration<_Rep2, _Period2> __dur2;
838 typedef typename common_type<__dur1,__dur2>::type __ct;
839 return __ct(__lhs).count() < __ct(__rhs).count();
840 }
841
842 #if __cpp_lib_three_way_comparison
843 template<typename _Rep1, typename _Period1,
844 typename _Rep2, typename _Period2>
845 requires three_way_comparable<common_type_t<_Rep1, _Rep2>>
846 constexpr auto
847 operator<=>(const duration<_Rep1, _Period1>& __lhs,
848 const duration<_Rep2, _Period2>& __rhs)
849 {
850 using __ct = common_type_t<duration<_Rep1, _Period1>,
851 duration<_Rep2, _Period2>>;
852 return __ct(__lhs).count() <=> __ct(__rhs).count();
853 }
854 #else
855 template<typename _Rep1, typename _Period1,
856 typename _Rep2, typename _Period2>
857 constexpr bool
858 operator!=(const duration<_Rep1, _Period1>& __lhs,
859 const duration<_Rep2, _Period2>& __rhs)
860 { return !(__lhs == __rhs); }
861 #endif
862
863 template<typename _Rep1, typename _Period1,
864 typename _Rep2, typename _Period2>
865 constexpr bool
866 operator<=(const duration<_Rep1, _Period1>& __lhs,
867 const duration<_Rep2, _Period2>& __rhs)
868 { return !(__rhs < __lhs); }
869
870 template<typename _Rep1, typename _Period1,
871 typename _Rep2, typename _Period2>
872 constexpr bool
873 operator>(const duration<_Rep1, _Period1>& __lhs,
874 const duration<_Rep2, _Period2>& __rhs)
875 { return __rhs < __lhs; }
876
877 template<typename _Rep1, typename _Period1,
878 typename _Rep2, typename _Period2>
879 constexpr bool
880 operator>=(const duration<_Rep1, _Period1>& __lhs,
881 const duration<_Rep2, _Period2>& __rhs)
882 { return !(__lhs < __rhs); }
883
884 /// @}
885
886 /// @cond undocumented
887 #ifdef _GLIBCXX_USE_C99_STDINT_TR1
888 # define _GLIBCXX_CHRONO_INT64_T int64_t
889 #elif defined __INT64_TYPE__
890 # define _GLIBCXX_CHRONO_INT64_T __INT64_TYPE__
891 #else
892 static_assert(std::numeric_limits<unsigned long long>::digits >= 64,
893 "Representation type for nanoseconds must have at least 64 bits");
894 # define _GLIBCXX_CHRONO_INT64_T long long
895 #endif
896 /// @endcond
897
898 /// nanoseconds
899 using nanoseconds = duration<_GLIBCXX_CHRONO_INT64_T, nano>;
900
901 /// microseconds
902 using microseconds = duration<_GLIBCXX_CHRONO_INT64_T, micro>;
903
904 /// milliseconds
905 using milliseconds = duration<_GLIBCXX_CHRONO_INT64_T, milli>;
906
907 /// seconds
908 using seconds = duration<_GLIBCXX_CHRONO_INT64_T>;
909
910 /// minutes
911 using minutes = duration<_GLIBCXX_CHRONO_INT64_T, ratio< 60>>;
912
913 /// hours
914 using hours = duration<_GLIBCXX_CHRONO_INT64_T, ratio<3600>>;
915
916 #if __cplusplus > 201703L
917 /// days
918 using days = duration<_GLIBCXX_CHRONO_INT64_T, ratio<86400>>;
919
920 /// weeks
921 using weeks = duration<_GLIBCXX_CHRONO_INT64_T, ratio<604800>>;
922
923 /// years
924 using years = duration<_GLIBCXX_CHRONO_INT64_T, ratio<31556952>>;
925
926 /// months
927 using months = duration<_GLIBCXX_CHRONO_INT64_T, ratio<2629746>>;
928 #endif // C++20
929
930 #undef _GLIBCXX_CHRONO_INT64_T
931
932 template<typename _Clock, typename _Dur>
933 class time_point
934 {
935 static_assert(__is_duration<_Dur>::value,
936 "duration must be a specialization of std::chrono::duration");
937
938 public:
939 typedef _Clock clock;
940 typedef _Dur duration;
941 typedef typename duration::rep rep;
942 typedef typename duration::period period;
943
944 constexpr time_point() : __d(duration::zero())
945 { }
946
947 constexpr explicit time_point(const duration& __dur)
948 : __d(__dur)
949 { }
950
951 // conversions
952 template<typename _Dur2,
953 typename = _Require<is_convertible<_Dur2, _Dur>>>
954 constexpr time_point(const time_point<clock, _Dur2>& __t)
955 : __d(__t.time_since_epoch())
956 { }
957
958 // observer
959 constexpr duration
960 time_since_epoch() const
961 { return __d; }
962
963 #if __cplusplus > 201703L
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
975 constexpr time_point&
976 operator--()
977 {
978 --__d;
979 return *this;
980 }
981
982 constexpr time_point
983 operator--(int)
984 { return time_point{__d--}; }
985 #endif
986
987 // arithmetic
988 _GLIBCXX17_CONSTEXPR time_point&
989 operator+=(const duration& __dur)
990 {
991 __d += __dur;
992 return *this;
993 }
994
995 _GLIBCXX17_CONSTEXPR time_point&
996 operator-=(const duration& __dur)
997 {
998 __d -= __dur;
999 return *this;
1000 }
1001
1002 // special values
1003 static constexpr time_point
1004 min() noexcept
1005 { return time_point(duration::min()); }
1006
1007 static constexpr time_point
1008 max() noexcept
1009 { return time_point(duration::max()); }
1010
1011 private:
1012 duration __d;
1013 };
1014
1015 /** Convert a `time_point` to use `duration` type `ToDur`.
1016 *
1017 * The result is the same time point as measured by the same clock, but
1018 * using the specified `duration` to represent the time.
1019 * If the time point cannot be represented accurately in the result type,
1020 * returns the result of integer truncation (i.e., rounded towards zero).
1021 *
1022 * @tparam _ToDur The `duration` type to use for the result.
1023 * @param __t A time point.
1024 * @return The value of `__t` converted to use type `_ToDur`.
1025 * @since C++11
1026 */
1027 template<typename _ToDur, typename _Clock, typename _Dur>
1028 _GLIBCXX_NODISCARD constexpr
1029 __enable_if_t<__is_duration<_ToDur>::value, time_point<_Clock, _ToDur>>
1030 time_point_cast(const time_point<_Clock, _Dur>& __t)
1031 {
1032 typedef time_point<_Clock, _ToDur> __time_point;
1033 return __time_point(duration_cast<_ToDur>(__t.time_since_epoch()));
1034 }
1035
1036 #if __cplusplus > 201402L
1037 /** Convert a `time_point` to type `ToDur` and round down.
1038 *
1039 * The result is the same time point as measured by the same clock, but
1040 * using the specified `duration` to represent the time.
1041 * If the time point cannot be represented exactly in the result type,
1042 * returns the closest value that is less than the argument.
1043 *
1044 * @tparam _ToDur The `duration` type to use for the result.
1045 * @param __t A time point.
1046 * @return The value of `__d` converted to type `_ToDur`.
1047 * @since C++17
1048 */
1049 template<typename _ToDur, typename _Clock, typename _Dur>
1050 [[nodiscard]] constexpr
1051 enable_if_t<__is_duration_v<_ToDur>, time_point<_Clock, _ToDur>>
1052 floor(const time_point<_Clock, _Dur>& __tp)
1053 {
1054 return time_point<_Clock, _ToDur>{
1055 chrono::floor<_ToDur>(__tp.time_since_epoch())};
1056 }
1057
1058 /** Convert a `time_point` to type `ToDur` and round up.
1059 *
1060 * The result is the same time point as measured by the same clock, but
1061 * using the specified `duration` to represent the time.
1062 * If the time point cannot be represented exactly in the result type,
1063 * returns the closest value that is greater than the argument.
1064 *
1065 * @tparam _ToDur The `duration` type to use for the result.
1066 * @param __t A time point.
1067 * @return The value of `__d` converted to type `_ToDur`.
1068 * @since C++17
1069 */
1070 template<typename _ToDur, typename _Clock, typename _Dur>
1071 [[nodiscard]] constexpr
1072 enable_if_t<__is_duration_v<_ToDur>, time_point<_Clock, _ToDur>>
1073 ceil(const time_point<_Clock, _Dur>& __tp)
1074 {
1075 return time_point<_Clock, _ToDur>{
1076 chrono::ceil<_ToDur>(__tp.time_since_epoch())};
1077 }
1078
1079 /** Convert a `time_point` to type `ToDur` and round to the closest value.
1080 *
1081 * The result is the same time point as measured by the same clock, but
1082 * using the specified `duration` to represent the time.
1083 * If the time point cannot be represented exactly in the result type,
1084 * returns the closest value, rounding ties to even.
1085 *
1086 * @tparam _ToDur The `duration` type to use for the result,
1087 * which must have a non-floating-point `rep` type.
1088 * @param __t A time point.
1089 * @return The value of `__d` converted to type `_ToDur`.
1090 * @since C++17
1091 */
1092 template<typename _ToDur, typename _Clock, typename _Dur>
1093 [[nodiscard]] constexpr
1094 enable_if_t<__is_duration_v<_ToDur>
1095 && !treat_as_floating_point_v<typename _ToDur::rep>,
1096 time_point<_Clock, _ToDur>>
1097 round(const time_point<_Clock, _Dur>& __tp)
1098 {
1099 return time_point<_Clock, _ToDur>{
1100 chrono::round<_ToDur>(__tp.time_since_epoch())};
1101 }
1102 #endif // C++17
1103
1104 /// @{
1105 /// @relates time_point
1106
1107 /// Adjust a time point forwards by the given duration.
1108 template<typename _Clock, typename _Dur1,
1109 typename _Rep2, typename _Period2>
1110 constexpr time_point<_Clock,
1111 typename common_type<_Dur1, duration<_Rep2, _Period2>>::type>
1112 operator+(const time_point<_Clock, _Dur1>& __lhs,
1113 const duration<_Rep2, _Period2>& __rhs)
1114 {
1115 typedef duration<_Rep2, _Period2> __dur2;
1116 typedef typename common_type<_Dur1,__dur2>::type __ct;
1117 typedef time_point<_Clock, __ct> __time_point;
1118 return __time_point(__lhs.time_since_epoch() + __rhs);
1119 }
1120
1121 /// Adjust a time point forwards by the given duration.
1122 template<typename _Rep1, typename _Period1,
1123 typename _Clock, typename _Dur2>
1124 constexpr time_point<_Clock,
1125 typename common_type<duration<_Rep1, _Period1>, _Dur2>::type>
1126 operator+(const duration<_Rep1, _Period1>& __lhs,
1127 const time_point<_Clock, _Dur2>& __rhs)
1128 {
1129 typedef duration<_Rep1, _Period1> __dur1;
1130 typedef typename common_type<__dur1,_Dur2>::type __ct;
1131 typedef time_point<_Clock, __ct> __time_point;
1132 return __time_point(__rhs.time_since_epoch() + __lhs);
1133 }
1134
1135 /// Adjust a time point backwards by the given duration.
1136 template<typename _Clock, typename _Dur1,
1137 typename _Rep2, typename _Period2>
1138 constexpr time_point<_Clock,
1139 typename common_type<_Dur1, duration<_Rep2, _Period2>>::type>
1140 operator-(const time_point<_Clock, _Dur1>& __lhs,
1141 const duration<_Rep2, _Period2>& __rhs)
1142 {
1143 typedef duration<_Rep2, _Period2> __dur2;
1144 typedef typename common_type<_Dur1,__dur2>::type __ct;
1145 typedef time_point<_Clock, __ct> __time_point;
1146 return __time_point(__lhs.time_since_epoch() -__rhs);
1147 }
1148
1149 /// The difference between two time points (as a duration)
1150 template<typename _Clock, typename _Dur1, typename _Dur2>
1151 constexpr typename common_type<_Dur1, _Dur2>::type
1152 operator-(const time_point<_Clock, _Dur1>& __lhs,
1153 const time_point<_Clock, _Dur2>& __rhs)
1154 { return __lhs.time_since_epoch() - __rhs.time_since_epoch(); }
1155 /// @}
1156
1157 /** @{
1158 * Comparisons for time_point
1159 * @relates chrono::time_point
1160 */
1161
1162 template<typename _Clock, typename _Dur1, typename _Dur2>
1163 constexpr bool
1164 operator==(const time_point<_Clock, _Dur1>& __lhs,
1165 const time_point<_Clock, _Dur2>& __rhs)
1166 { return __lhs.time_since_epoch() == __rhs.time_since_epoch(); }
1167
1168 #if __cpp_lib_three_way_comparison
1169 template<typename _Clock, typename _Dur1,
1170 three_way_comparable_with<_Dur1> _Dur2>
1171 constexpr auto
1172 operator<=>(const time_point<_Clock, _Dur1>& __lhs,
1173 const time_point<_Clock, _Dur2>& __rhs)
1174 { return __lhs.time_since_epoch() <=> __rhs.time_since_epoch(); }
1175 #else
1176 template<typename _Clock, typename _Dur1, typename _Dur2>
1177 constexpr bool
1178 operator!=(const time_point<_Clock, _Dur1>& __lhs,
1179 const time_point<_Clock, _Dur2>& __rhs)
1180 { return !(__lhs == __rhs); }
1181 #endif
1182
1183 template<typename _Clock, typename _Dur1, typename _Dur2>
1184 constexpr bool
1185 operator<(const time_point<_Clock, _Dur1>& __lhs,
1186 const time_point<_Clock, _Dur2>& __rhs)
1187 { return __lhs.time_since_epoch() < __rhs.time_since_epoch(); }
1188
1189 template<typename _Clock, typename _Dur1, typename _Dur2>
1190 constexpr bool
1191 operator<=(const time_point<_Clock, _Dur1>& __lhs,
1192 const time_point<_Clock, _Dur2>& __rhs)
1193 { return !(__rhs < __lhs); }
1194
1195 template<typename _Clock, typename _Dur1, typename _Dur2>
1196 constexpr bool
1197 operator>(const time_point<_Clock, _Dur1>& __lhs,
1198 const time_point<_Clock, _Dur2>& __rhs)
1199 { return __rhs < __lhs; }
1200
1201 template<typename _Clock, typename _Dur1, typename _Dur2>
1202 constexpr bool
1203 operator>=(const time_point<_Clock, _Dur1>& __lhs,
1204 const time_point<_Clock, _Dur2>& __rhs)
1205 { return !(__lhs < __rhs); }
1206
1207 /// @}
1208 /// @} group chrono
1209
1210 // Clocks.
1211
1212 // Why nanosecond resolution as the default?
1213 // Why have std::system_clock always count in the highest
1214 // resolution (ie nanoseconds), even if on some OSes the low 3
1215 // or 9 decimal digits will be always zero? This allows later
1216 // implementations to change the system_clock::now()
1217 // implementation any time to provide better resolution without
1218 // changing function signature or units.
1219
1220 // To support the (forward) evolution of the library's defined
1221 // clocks, wrap inside inline namespace so that the current
1222 // defintions of system_clock, steady_clock, and
1223 // high_resolution_clock types are uniquely mangled. This way, new
1224 // code can use the latests clocks, while the library can contain
1225 // compatibility definitions for previous versions. At some
1226 // point, when these clocks settle down, the inlined namespaces
1227 // can be removed. XXX GLIBCXX_ABI Deprecated
1228 _GLIBCXX_BEGIN_INLINE_ABI_NAMESPACE(_V2)
1229
1230 /**
1231 * @brief System clock.
1232 *
1233 * Time returned represents wall time from the system-wide clock.
1234 * @ingroup chrono
1235 */
1236 struct system_clock
1237 {
1238 typedef chrono::nanoseconds duration;
1239 typedef duration::rep rep;
1240 typedef duration::period period;
1241 typedef chrono::time_point<system_clock, duration> time_point;
1242
1243 static_assert(system_clock::duration::min()
1244 < system_clock::duration::zero(),
1245 "a clock's minimum duration cannot be less than its epoch");
1246
1247 static constexpr bool is_steady = false;
1248
1249 static time_point
1250 now() noexcept;
1251
1252 // Map to C API
1253 static std::time_t
1254 to_time_t(const time_point& __t) noexcept
1255 {
1256 return std::time_t(duration_cast<chrono::seconds>
1257 (__t.time_since_epoch()).count());
1258 }
1259
1260 static time_point
1261 from_time_t(std::time_t __t) noexcept
1262 {
1263 typedef chrono::time_point<system_clock, seconds> __from;
1264 return time_point_cast<system_clock::duration>
1265 (__from(chrono::seconds(__t)));
1266 }
1267 };
1268
1269
1270 /**
1271 * @brief Monotonic clock
1272 *
1273 * Time returned has the property of only increasing at a uniform rate.
1274 * @ingroup chrono
1275 */
1276 struct steady_clock
1277 {
1278 typedef chrono::nanoseconds duration;
1279 typedef duration::rep rep;
1280 typedef duration::period period;
1281 typedef chrono::time_point<steady_clock, duration> time_point;
1282
1283 static constexpr bool is_steady = true;
1284
1285 static time_point
1286 now() noexcept;
1287 };
1288
1289
1290 /**
1291 * @brief Highest-resolution clock
1292 *
1293 * This is the clock "with the shortest tick period." Alias to
1294 * std::system_clock until higher-than-nanosecond definitions
1295 * become feasible.
1296 * @ingroup chrono
1297 */
1298 using high_resolution_clock = system_clock;
1299
1300 _GLIBCXX_END_INLINE_ABI_NAMESPACE(_V2)
1301
1302 #if __cplusplus >= 202002L
1303 /// @addtogroup chrono
1304 /// @{
1305 template<typename _Duration>
1306 using sys_time = time_point<system_clock, _Duration>;
1307 using sys_seconds = sys_time<seconds>;
1308 using sys_days = sys_time<days>;
1309
1310 using file_clock = ::std::filesystem::__file_clock;
1311
1312 template<typename _Duration>
1313 using file_time = time_point<file_clock, _Duration>;
1314
1315 template<> struct is_clock<system_clock> : true_type { };
1316 template<> struct is_clock<steady_clock> : true_type { };
1317 template<> struct is_clock<file_clock> : true_type { };
1318
1319 template<> inline constexpr bool is_clock_v<system_clock> = true;
1320 template<> inline constexpr bool is_clock_v<steady_clock> = true;
1321 template<> inline constexpr bool is_clock_v<file_clock> = true;
1322 /// @}
1323 #endif // C++20
1324 } // namespace chrono
1325
1326 #if __cplusplus >= 201402L
1327 #define __cpp_lib_chrono_udls 201304L
1328
1329 inline namespace literals
1330 {
1331 /** ISO C++ 2014 namespace for suffixes for duration literals.
1332 *
1333 * These suffixes can be used to create `chrono::duration` values with
1334 * tick periods of hours, minutes, seconds, milliseconds, microseconds
1335 * or nanoseconds. For example, `std::chrono::seconds(5)` can be written
1336 * as `5s` after making the suffix visible in the current scope.
1337 * The suffixes can be made visible by a using-directive or
1338 * using-declaration such as:
1339 * - `using namespace std::chrono_literals;`
1340 * - `using namespace std::literals;`
1341 * - `using namespace std::chrono;`
1342 * - `using namespace std;`
1343 * - `using std::chrono_literals::operator""s;`
1344 *
1345 * The result of these suffixes on an integer literal is one of the
1346 * standard typedefs such as `std::chrono::hours`.
1347 * The result on a floating-point literal is a duration type with the
1348 * specified tick period and an unspecified floating-point representation,
1349 * for example `1.5e2ms` might be equivalent to
1350 * `chrono::duration<long double, chrono::milli>(1.5e2)`.
1351 *
1352 * @since C+14
1353 * @ingroup chrono
1354 */
1355 inline namespace chrono_literals
1356 {
1357 /// @addtogroup chrono
1358 /// @{
1359
1360 #pragma GCC diagnostic push
1361 #pragma GCC diagnostic ignored "-Wliteral-suffix"
1362 /// @cond undocumented
1363 template<typename _Dur, char... _Digits>
1364 constexpr _Dur __check_overflow()
1365 {
1366 using _Val = __parse_int::_Parse_int<_Digits...>;
1367 constexpr typename _Dur::rep __repval = _Val::value;
1368 static_assert(__repval >= 0 && __repval == _Val::value,
1369 "literal value cannot be represented by duration type");
1370 return _Dur(__repval);
1371 }
1372 /// @endcond
1373
1374 /// Literal suffix for durations representing non-integer hours
1375 constexpr chrono::duration<long double, ratio<3600,1>>
1376 operator""h(long double __hours)
1377 { return chrono::duration<long double, ratio<3600,1>>{__hours}; }
1378
1379 /// Literal suffix for durations of type `std::chrono::hours`
1380 template <char... _Digits>
1381 constexpr chrono::hours
1382 operator""h()
1383 { return __check_overflow<chrono::hours, _Digits...>(); }
1384
1385 /// Literal suffix for durations representing non-integer minutes
1386 constexpr chrono::duration<long double, ratio<60,1>>
1387 operator""min(long double __mins)
1388 { return chrono::duration<long double, ratio<60,1>>{__mins}; }
1389
1390 /// Literal suffix for durations of type `std::chrono::minutes`
1391 template <char... _Digits>
1392 constexpr chrono::minutes
1393 operator""min()
1394 { return __check_overflow<chrono::minutes, _Digits...>(); }
1395
1396 /// Literal suffix for durations representing non-integer seconds
1397 constexpr chrono::duration<long double>
1398 operator""s(long double __secs)
1399 { return chrono::duration<long double>{__secs}; }
1400
1401 /// Literal suffix for durations of type `std::chrono::seconds`
1402 template <char... _Digits>
1403 constexpr chrono::seconds
1404 operator""s()
1405 { return __check_overflow<chrono::seconds, _Digits...>(); }
1406
1407 /// Literal suffix for durations representing non-integer milliseconds
1408 constexpr chrono::duration<long double, milli>
1409 operator""ms(long double __msecs)
1410 { return chrono::duration<long double, milli>{__msecs}; }
1411
1412 /// Literal suffix for durations of type `std::chrono::milliseconds`
1413 template <char... _Digits>
1414 constexpr chrono::milliseconds
1415 operator""ms()
1416 { return __check_overflow<chrono::milliseconds, _Digits...>(); }
1417
1418 /// Literal suffix for durations representing non-integer microseconds
1419 constexpr chrono::duration<long double, micro>
1420 operator""us(long double __usecs)
1421 { return chrono::duration<long double, micro>{__usecs}; }
1422
1423 /// Literal suffix for durations of type `std::chrono::microseconds`
1424 template <char... _Digits>
1425 constexpr chrono::microseconds
1426 operator""us()
1427 { return __check_overflow<chrono::microseconds, _Digits...>(); }
1428
1429 /// Literal suffix for durations representing non-integer nanoseconds
1430 constexpr chrono::duration<long double, nano>
1431 operator""ns(long double __nsecs)
1432 { return chrono::duration<long double, nano>{__nsecs}; }
1433
1434 /// Literal suffix for durations of type `std::chrono::nanoseconds`
1435 template <char... _Digits>
1436 constexpr chrono::nanoseconds
1437 operator""ns()
1438 { return __check_overflow<chrono::nanoseconds, _Digits...>(); }
1439
1440 #pragma GCC diagnostic pop
1441 /// @}
1442 } // inline namespace chrono_literals
1443 } // inline namespace literals
1444
1445 namespace chrono
1446 {
1447 using namespace literals::chrono_literals;
1448 } // namespace chrono
1449 #endif // C++14
1450
1451 #if __cplusplus >= 201703L
1452 namespace filesystem
1453 {
1454 struct __file_clock
1455 {
1456 using duration = chrono::nanoseconds;
1457 using rep = duration::rep;
1458 using period = duration::period;
1459 using time_point = chrono::time_point<__file_clock>;
1460 static constexpr bool is_steady = false;
1461
1462 static time_point
1463 now() noexcept
1464 { return _S_from_sys(chrono::system_clock::now()); }
1465
1466 #if __cplusplus > 201703L
1467 template<typename _Dur>
1468 static
1469 chrono::file_time<_Dur>
1470 from_sys(const chrono::sys_time<_Dur>& __t) noexcept
1471 { return _S_from_sys(__t); }
1472
1473 // For internal use only
1474 template<typename _Dur>
1475 static
1476 chrono::sys_time<_Dur>
1477 to_sys(const chrono::file_time<_Dur>& __t) noexcept
1478 { return _S_to_sys(__t); }
1479 #endif // C++20
1480
1481 private:
1482 using __sys_clock = chrono::system_clock;
1483
1484 // This clock's (unspecified) epoch is 2174-01-01 00:00:00 UTC.
1485 // A signed 64-bit duration with nanosecond resolution gives roughly
1486 // +/- 292 years, which covers the 1901-2446 date range for ext4.
1487 static constexpr chrono::seconds _S_epoch_diff{6437664000};
1488
1489 protected:
1490 // For internal use only
1491 template<typename _Dur>
1492 static
1493 chrono::time_point<__file_clock, _Dur>
1494 _S_from_sys(const chrono::time_point<__sys_clock, _Dur>& __t) noexcept
1495 {
1496 using __file_time = chrono::time_point<__file_clock, _Dur>;
1497 return __file_time{__t.time_since_epoch()} - _S_epoch_diff;
1498 }
1499
1500 // For internal use only
1501 template<typename _Dur>
1502 static
1503 chrono::time_point<__sys_clock, _Dur>
1504 _S_to_sys(const chrono::time_point<__file_clock, _Dur>& __t) noexcept
1505 {
1506 using __sys_time = chrono::time_point<__sys_clock, _Dur>;
1507 return __sys_time{__t.time_since_epoch()} + _S_epoch_diff;
1508 }
1509 };
1510 } // namespace filesystem
1511 #endif // C++17
1512
1513 _GLIBCXX_END_NAMESPACE_VERSION
1514 } // namespace std
1515
1516 #endif // C++11
1517
1518 #endif //_GLIBCXX_CHRONO_H