1 // <chrono> -*- C++ -*-
3 // Copyright (C) 2008-2017 Free Software Foundation, Inc.
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)
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.
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.
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/>.
25 /** @file include/chrono
26 * This is a Standard C++ Library header.
29 #ifndef _GLIBCXX_CHRONO
30 #define _GLIBCXX_CHRONO 1
32 #pragma GCC system_header
34 #if __cplusplus < 201103L
35 # include <bits/c++0x_warning.h>
39 #include <type_traits>
42 #include <bits/parse_numbers.h> // for literals support.
44 #ifdef _GLIBCXX_USE_C99_STDINT_TR1
46 namespace std _GLIBCXX_VISIBILITY(default)
48 _GLIBCXX_BEGIN_NAMESPACE_VERSION
51 * @defgroup chrono Time
54 * Classes and functions for time.
58 /** @namespace std::chrono
59 * @brief ISO C++ 2011 entities sub-namespace for time and date.
63 template<typename _Rep, typename _Period = ratio<1>>
66 template<typename _Clock, typename _Dur = typename _Clock::duration>
70 // 20.11.4.3 specialization of common_type (for duration, sfinae-friendly)
72 template<typename _CT, typename _Period1, typename _Period2>
73 struct __duration_common_type_wrapper
76 typedef __static_gcd<_Period1::num, _Period2::num> __gcd_num;
77 typedef __static_gcd<_Period1::den, _Period2::den> __gcd_den;
78 typedef typename _CT::type __cr;
79 typedef ratio<__gcd_num::value,
80 (_Period1::den / __gcd_den::value) * _Period2::den> __r;
82 typedef __success_type<chrono::duration<__cr, __r>> type;
85 template<typename _Period1, typename _Period2>
86 struct __duration_common_type_wrapper<__failure_type, _Period1, _Period2>
87 { typedef __failure_type type; };
89 template<typename _Rep1, typename _Period1, typename _Rep2, typename _Period2>
90 struct common_type<chrono::duration<_Rep1, _Period1>,
91 chrono::duration<_Rep2, _Period2>>
92 : public __duration_common_type_wrapper<typename __member_type_wrapper<
93 common_type<_Rep1, _Rep2>>::type, _Period1, _Period2>::type
96 // 20.11.4.3 specialization of common_type (for time_point, sfinae-friendly)
98 template<typename _CT, typename _Clock>
99 struct __timepoint_common_type_wrapper
101 typedef __success_type<chrono::time_point<_Clock, typename _CT::type>>
105 template<typename _Clock>
106 struct __timepoint_common_type_wrapper<__failure_type, _Clock>
107 { typedef __failure_type type; };
109 template<typename _Clock, typename _Duration1, typename _Duration2>
110 struct common_type<chrono::time_point<_Clock, _Duration1>,
111 chrono::time_point<_Clock, _Duration2>>
112 : public __timepoint_common_type_wrapper<typename __member_type_wrapper<
113 common_type<_Duration1, _Duration2>>::type, _Clock>::type
118 // Primary template for duration_cast impl.
119 template<typename _ToDur, typename _CF, typename _CR,
120 bool _NumIsOne = false, bool _DenIsOne = false>
121 struct __duration_cast_impl
123 template<typename _Rep, typename _Period>
124 static constexpr _ToDur
125 __cast(const duration<_Rep, _Period>& __d)
127 typedef typename _ToDur::rep __to_rep;
128 return _ToDur(static_cast<__to_rep>(static_cast<_CR>(__d.count())
129 * static_cast<_CR>(_CF::num)
130 / static_cast<_CR>(_CF::den)));
134 template<typename _ToDur, typename _CF, typename _CR>
135 struct __duration_cast_impl<_ToDur, _CF, _CR, true, true>
137 template<typename _Rep, typename _Period>
138 static constexpr _ToDur
139 __cast(const duration<_Rep, _Period>& __d)
141 typedef typename _ToDur::rep __to_rep;
142 return _ToDur(static_cast<__to_rep>(__d.count()));
146 template<typename _ToDur, typename _CF, typename _CR>
147 struct __duration_cast_impl<_ToDur, _CF, _CR, true, false>
149 template<typename _Rep, typename _Period>
150 static constexpr _ToDur
151 __cast(const duration<_Rep, _Period>& __d)
153 typedef typename _ToDur::rep __to_rep;
154 return _ToDur(static_cast<__to_rep>(
155 static_cast<_CR>(__d.count()) / static_cast<_CR>(_CF::den)));
159 template<typename _ToDur, typename _CF, typename _CR>
160 struct __duration_cast_impl<_ToDur, _CF, _CR, false, true>
162 template<typename _Rep, typename _Period>
163 static constexpr _ToDur
164 __cast(const duration<_Rep, _Period>& __d)
166 typedef typename _ToDur::rep __to_rep;
167 return _ToDur(static_cast<__to_rep>(
168 static_cast<_CR>(__d.count()) * static_cast<_CR>(_CF::num)));
172 template<typename _Tp>
177 template<typename _Rep, typename _Period>
178 struct __is_duration<duration<_Rep, _Period>>
182 template<typename _Tp>
183 using __enable_if_is_duration
184 = typename enable_if<__is_duration<_Tp>::value, _Tp>::type;
186 template<typename _Tp>
187 using __disable_if_is_duration
188 = typename enable_if<!__is_duration<_Tp>::value, _Tp>::type;
191 template<typename _ToDur, typename _Rep, typename _Period>
192 constexpr __enable_if_is_duration<_ToDur>
193 duration_cast(const duration<_Rep, _Period>& __d)
195 typedef typename _ToDur::period __to_period;
196 typedef typename _ToDur::rep __to_rep;
197 typedef ratio_divide<_Period, __to_period> __cf;
198 typedef typename common_type<__to_rep, _Rep, intmax_t>::type
200 typedef __duration_cast_impl<_ToDur, __cf, __cr,
201 __cf::num == 1, __cf::den == 1> __dc;
202 return __dc::__cast(__d);
205 /// treat_as_floating_point
206 template<typename _Rep>
207 struct treat_as_floating_point
208 : is_floating_point<_Rep>
211 #if __cplusplus > 201402L
212 template <typename _Rep>
213 inline constexpr bool treat_as_floating_point_v =
214 treat_as_floating_point<_Rep>::value;
217 #if __cplusplus > 201402L
218 # define __cpp_lib_chrono 201510
220 template<typename _ToDur, typename _Rep, typename _Period>
221 constexpr __enable_if_is_duration<_ToDur>
222 floor(const duration<_Rep, _Period>& __d)
224 auto __to = chrono::duration_cast<_ToDur>(__d);
226 return __to - _ToDur{1};
230 template<typename _ToDur, typename _Rep, typename _Period>
231 constexpr __enable_if_is_duration<_ToDur>
232 ceil(const duration<_Rep, _Period>& __d)
234 auto __to = chrono::duration_cast<_ToDur>(__d);
236 return __to + _ToDur{1};
240 template <typename _ToDur, typename _Rep, typename _Period>
241 constexpr enable_if_t<
242 __and_<__is_duration<_ToDur>,
243 __not_<treat_as_floating_point<typename _ToDur::rep>>>::value,
245 round(const duration<_Rep, _Period>& __d)
247 _ToDur __t0 = chrono::floor<_ToDur>(__d);
248 _ToDur __t1 = __t0 + _ToDur{1};
249 auto __diff0 = __d - __t0;
250 auto __diff1 = __t1 - __d;
251 if (__diff0 == __diff1)
253 if (__t0.count() & 1)
257 else if (__diff0 < __diff1)
262 template<typename _Rep, typename _Period>
264 enable_if_t<numeric_limits<_Rep>::is_signed, duration<_Rep, _Period>>
265 abs(duration<_Rep, _Period> __d)
267 if (__d >= __d.zero())
274 template<typename _Rep>
275 struct duration_values
277 static constexpr _Rep
281 static constexpr _Rep
283 { return numeric_limits<_Rep>::max(); }
285 static constexpr _Rep
287 { return numeric_limits<_Rep>::lowest(); }
290 template<typename _Tp>
295 template<intmax_t _Num, intmax_t _Den>
296 struct __is_ratio<ratio<_Num, _Den>>
301 template<typename _Rep, typename _Period>
305 template<typename _Rep2>
306 using __is_float = treat_as_floating_point<_Rep2>;
308 // _Period2 is an exact multiple of _Period
309 template<typename _Period2>
311 = __bool_constant<ratio_divide<_Period2, _Period>::den == 1>;
316 typedef _Period period;
318 static_assert(!__is_duration<_Rep>::value, "rep cannot be a duration");
319 static_assert(__is_ratio<_Period>::value,
320 "period must be a specialization of ratio");
321 static_assert(_Period::num > 0, "period must be positive");
323 // 20.11.5.1 construction / copy / destroy
324 constexpr duration() = default;
326 duration(const duration&) = default;
328 template<typename _Rep2, typename = _Require<
329 is_convertible<_Rep2, rep>,
330 __or_<__is_float<rep>, __not_<__is_float<_Rep2>>>>>
331 constexpr explicit duration(const _Rep2& __rep)
332 : __r(static_cast<rep>(__rep)) { }
334 template<typename _Rep2, typename _Period2, typename = _Require<
335 __or_<__is_float<rep>,
336 __and_<__is_harmonic<_Period2>,
337 __not_<__is_float<_Rep2>>>>>>
338 constexpr duration(const duration<_Rep2, _Period2>& __d)
339 : __r(duration_cast<duration>(__d).count()) { }
341 ~duration() = default;
342 duration& operator=(const duration&) = default;
344 // 20.11.5.2 observer
349 // 20.11.5.3 arithmetic
356 { return duration(-__r); }
358 _GLIBCXX17_CONSTEXPR duration&
365 _GLIBCXX17_CONSTEXPR duration
367 { return duration(__r++); }
369 _GLIBCXX17_CONSTEXPR duration&
376 _GLIBCXX17_CONSTEXPR duration
378 { return duration(__r--); }
380 _GLIBCXX17_CONSTEXPR duration&
381 operator+=(const duration& __d)
387 _GLIBCXX17_CONSTEXPR duration&
388 operator-=(const duration& __d)
394 _GLIBCXX17_CONSTEXPR duration&
395 operator*=(const rep& __rhs)
401 _GLIBCXX17_CONSTEXPR duration&
402 operator/=(const rep& __rhs)
409 template<typename _Rep2 = rep>
411 typename enable_if<!treat_as_floating_point<_Rep2>::value,
413 operator%=(const rep& __rhs)
419 template<typename _Rep2 = rep>
421 typename enable_if<!treat_as_floating_point<_Rep2>::value,
423 operator%=(const duration& __d)
429 // 20.11.5.4 special values
430 static constexpr duration
432 { return duration(duration_values<rep>::zero()); }
434 static constexpr duration
436 { return duration(duration_values<rep>::min()); }
438 static constexpr duration
440 { return duration(duration_values<rep>::max()); }
446 template<typename _Rep1, typename _Period1,
447 typename _Rep2, typename _Period2>
448 constexpr typename common_type<duration<_Rep1, _Period1>,
449 duration<_Rep2, _Period2>>::type
450 operator+(const duration<_Rep1, _Period1>& __lhs,
451 const duration<_Rep2, _Period2>& __rhs)
453 typedef duration<_Rep1, _Period1> __dur1;
454 typedef duration<_Rep2, _Period2> __dur2;
455 typedef typename common_type<__dur1,__dur2>::type __cd;
456 return __cd(__cd(__lhs).count() + __cd(__rhs).count());
459 template<typename _Rep1, typename _Period1,
460 typename _Rep2, typename _Period2>
461 constexpr typename common_type<duration<_Rep1, _Period1>,
462 duration<_Rep2, _Period2>>::type
463 operator-(const duration<_Rep1, _Period1>& __lhs,
464 const duration<_Rep2, _Period2>& __rhs)
466 typedef duration<_Rep1, _Period1> __dur1;
467 typedef duration<_Rep2, _Period2> __dur2;
468 typedef typename common_type<__dur1,__dur2>::type __cd;
469 return __cd(__cd(__lhs).count() - __cd(__rhs).count());
472 // SFINAE helper to obtain common_type<_Rep1, _Rep2> only if _Rep2
473 // is implicitly convertible to it.
474 template<typename _Rep1, typename _Rep2,
475 typename _CRep = typename common_type<_Rep1, _Rep2>::type>
477 = typename enable_if<is_convertible<_Rep2, _CRep>::value, _CRep>::type;
479 template<typename _Rep1, typename _Period, typename _Rep2>
480 constexpr duration<__common_rep_t<_Rep1, _Rep2>, _Period>
481 operator*(const duration<_Rep1, _Period>& __d, const _Rep2& __s)
483 typedef duration<typename common_type<_Rep1, _Rep2>::type, _Period>
485 return __cd(__cd(__d).count() * __s);
488 template<typename _Rep1, typename _Rep2, typename _Period>
489 constexpr duration<__common_rep_t<_Rep2, _Rep1>, _Period>
490 operator*(const _Rep1& __s, const duration<_Rep2, _Period>& __d)
491 { return __d * __s; }
493 template<typename _Rep1, typename _Period, typename _Rep2>
495 duration<__common_rep_t<_Rep1, __disable_if_is_duration<_Rep2>>, _Period>
496 operator/(const duration<_Rep1, _Period>& __d, const _Rep2& __s)
498 typedef duration<typename common_type<_Rep1, _Rep2>::type, _Period>
500 return __cd(__cd(__d).count() / __s);
503 template<typename _Rep1, typename _Period1,
504 typename _Rep2, typename _Period2>
505 constexpr typename common_type<_Rep1, _Rep2>::type
506 operator/(const duration<_Rep1, _Period1>& __lhs,
507 const duration<_Rep2, _Period2>& __rhs)
509 typedef duration<_Rep1, _Period1> __dur1;
510 typedef duration<_Rep2, _Period2> __dur2;
511 typedef typename common_type<__dur1,__dur2>::type __cd;
512 return __cd(__lhs).count() / __cd(__rhs).count();
516 template<typename _Rep1, typename _Period, typename _Rep2>
518 duration<__common_rep_t<_Rep1, __disable_if_is_duration<_Rep2>>, _Period>
519 operator%(const duration<_Rep1, _Period>& __d, const _Rep2& __s)
521 typedef duration<typename common_type<_Rep1, _Rep2>::type, _Period>
523 return __cd(__cd(__d).count() % __s);
526 template<typename _Rep1, typename _Period1,
527 typename _Rep2, typename _Period2>
528 constexpr typename common_type<duration<_Rep1, _Period1>,
529 duration<_Rep2, _Period2>>::type
530 operator%(const duration<_Rep1, _Period1>& __lhs,
531 const duration<_Rep2, _Period2>& __rhs)
533 typedef duration<_Rep1, _Period1> __dur1;
534 typedef duration<_Rep2, _Period2> __dur2;
535 typedef typename common_type<__dur1,__dur2>::type __cd;
536 return __cd(__cd(__lhs).count() % __cd(__rhs).count());
540 template<typename _Rep1, typename _Period1,
541 typename _Rep2, typename _Period2>
543 operator==(const duration<_Rep1, _Period1>& __lhs,
544 const duration<_Rep2, _Period2>& __rhs)
546 typedef duration<_Rep1, _Period1> __dur1;
547 typedef duration<_Rep2, _Period2> __dur2;
548 typedef typename common_type<__dur1,__dur2>::type __ct;
549 return __ct(__lhs).count() == __ct(__rhs).count();
552 template<typename _Rep1, typename _Period1,
553 typename _Rep2, typename _Period2>
555 operator<(const duration<_Rep1, _Period1>& __lhs,
556 const duration<_Rep2, _Period2>& __rhs)
558 typedef duration<_Rep1, _Period1> __dur1;
559 typedef duration<_Rep2, _Period2> __dur2;
560 typedef typename common_type<__dur1,__dur2>::type __ct;
561 return __ct(__lhs).count() < __ct(__rhs).count();
564 template<typename _Rep1, typename _Period1,
565 typename _Rep2, typename _Period2>
567 operator!=(const duration<_Rep1, _Period1>& __lhs,
568 const duration<_Rep2, _Period2>& __rhs)
569 { return !(__lhs == __rhs); }
571 template<typename _Rep1, typename _Period1,
572 typename _Rep2, typename _Period2>
574 operator<=(const duration<_Rep1, _Period1>& __lhs,
575 const duration<_Rep2, _Period2>& __rhs)
576 { return !(__rhs < __lhs); }
578 template<typename _Rep1, typename _Period1,
579 typename _Rep2, typename _Period2>
581 operator>(const duration<_Rep1, _Period1>& __lhs,
582 const duration<_Rep2, _Period2>& __rhs)
583 { return __rhs < __lhs; }
585 template<typename _Rep1, typename _Period1,
586 typename _Rep2, typename _Period2>
588 operator>=(const duration<_Rep1, _Period1>& __lhs,
589 const duration<_Rep2, _Period2>& __rhs)
590 { return !(__lhs < __rhs); }
593 typedef duration<int64_t, nano> nanoseconds;
596 typedef duration<int64_t, micro> microseconds;
599 typedef duration<int64_t, milli> milliseconds;
602 typedef duration<int64_t> seconds;
605 typedef duration<int64_t, ratio< 60>> minutes;
608 typedef duration<int64_t, ratio<3600>> hours;
611 template<typename _Clock, typename _Dur>
614 typedef _Clock clock;
615 typedef _Dur duration;
616 typedef typename duration::rep rep;
617 typedef typename duration::period period;
619 constexpr time_point() : __d(duration::zero())
622 constexpr explicit time_point(const duration& __dur)
627 template<typename _Dur2,
628 typename = _Require<is_convertible<_Dur2, _Dur>>>
629 constexpr time_point(const time_point<clock, _Dur2>& __t)
630 : __d(__t.time_since_epoch())
635 time_since_epoch() const
639 _GLIBCXX17_CONSTEXPR time_point&
640 operator+=(const duration& __dur)
646 _GLIBCXX17_CONSTEXPR time_point&
647 operator-=(const duration& __dur)
654 static constexpr time_point
656 { return time_point(duration::min()); }
658 static constexpr time_point
660 { return time_point(duration::max()); }
667 template<typename _ToDur, typename _Clock, typename _Dur>
668 constexpr typename enable_if<__is_duration<_ToDur>::value,
669 time_point<_Clock, _ToDur>>::type
670 time_point_cast(const time_point<_Clock, _Dur>& __t)
672 typedef time_point<_Clock, _ToDur> __time_point;
673 return __time_point(duration_cast<_ToDur>(__t.time_since_epoch()));
676 #if __cplusplus > 201402L
677 template<typename _ToDur, typename _Clock, typename _Dur>
679 enable_if_t<__is_duration<_ToDur>::value, time_point<_Clock, _ToDur>>
680 floor(const time_point<_Clock, _Dur>& __tp)
682 return time_point<_Clock, _ToDur>{
683 chrono::floor<_ToDur>(__tp.time_since_epoch())};
686 template<typename _ToDur, typename _Clock, typename _Dur>
688 enable_if_t<__is_duration<_ToDur>::value, time_point<_Clock, _ToDur>>
689 ceil(const time_point<_Clock, _Dur>& __tp)
691 return time_point<_Clock, _ToDur>{
692 chrono::ceil<_ToDur>(__tp.time_since_epoch())};
695 template<typename _ToDur, typename _Clock, typename _Dur>
696 constexpr enable_if_t<
697 __and_<__is_duration<_ToDur>,
698 __not_<treat_as_floating_point<typename _ToDur::rep>>>::value,
699 time_point<_Clock, _ToDur>>
700 round(const time_point<_Clock, _Dur>& __tp)
702 return time_point<_Clock, _ToDur>{
703 chrono::round<_ToDur>(__tp.time_since_epoch())};
707 template<typename _Clock, typename _Dur1,
708 typename _Rep2, typename _Period2>
709 constexpr time_point<_Clock,
710 typename common_type<_Dur1, duration<_Rep2, _Period2>>::type>
711 operator+(const time_point<_Clock, _Dur1>& __lhs,
712 const duration<_Rep2, _Period2>& __rhs)
714 typedef duration<_Rep2, _Period2> __dur2;
715 typedef typename common_type<_Dur1,__dur2>::type __ct;
716 typedef time_point<_Clock, __ct> __time_point;
717 return __time_point(__lhs.time_since_epoch() + __rhs);
720 template<typename _Rep1, typename _Period1,
721 typename _Clock, typename _Dur2>
722 constexpr time_point<_Clock,
723 typename common_type<duration<_Rep1, _Period1>, _Dur2>::type>
724 operator+(const duration<_Rep1, _Period1>& __lhs,
725 const time_point<_Clock, _Dur2>& __rhs)
727 typedef duration<_Rep1, _Period1> __dur1;
728 typedef typename common_type<__dur1,_Dur2>::type __ct;
729 typedef time_point<_Clock, __ct> __time_point;
730 return __time_point(__rhs.time_since_epoch() + __lhs);
733 template<typename _Clock, typename _Dur1,
734 typename _Rep2, typename _Period2>
735 constexpr time_point<_Clock,
736 typename common_type<_Dur1, duration<_Rep2, _Period2>>::type>
737 operator-(const time_point<_Clock, _Dur1>& __lhs,
738 const duration<_Rep2, _Period2>& __rhs)
740 typedef duration<_Rep2, _Period2> __dur2;
741 typedef typename common_type<_Dur1,__dur2>::type __ct;
742 typedef time_point<_Clock, __ct> __time_point;
743 return __time_point(__lhs.time_since_epoch() -__rhs);
746 template<typename _Clock, typename _Dur1, typename _Dur2>
747 constexpr typename common_type<_Dur1, _Dur2>::type
748 operator-(const time_point<_Clock, _Dur1>& __lhs,
749 const time_point<_Clock, _Dur2>& __rhs)
750 { return __lhs.time_since_epoch() - __rhs.time_since_epoch(); }
752 template<typename _Clock, typename _Dur1, typename _Dur2>
754 operator==(const time_point<_Clock, _Dur1>& __lhs,
755 const time_point<_Clock, _Dur2>& __rhs)
756 { return __lhs.time_since_epoch() == __rhs.time_since_epoch(); }
758 template<typename _Clock, typename _Dur1, typename _Dur2>
760 operator!=(const time_point<_Clock, _Dur1>& __lhs,
761 const time_point<_Clock, _Dur2>& __rhs)
762 { return !(__lhs == __rhs); }
764 template<typename _Clock, typename _Dur1, typename _Dur2>
766 operator<(const time_point<_Clock, _Dur1>& __lhs,
767 const time_point<_Clock, _Dur2>& __rhs)
768 { return __lhs.time_since_epoch() < __rhs.time_since_epoch(); }
770 template<typename _Clock, typename _Dur1, typename _Dur2>
772 operator<=(const time_point<_Clock, _Dur1>& __lhs,
773 const time_point<_Clock, _Dur2>& __rhs)
774 { return !(__rhs < __lhs); }
776 template<typename _Clock, typename _Dur1, typename _Dur2>
778 operator>(const time_point<_Clock, _Dur1>& __lhs,
779 const time_point<_Clock, _Dur2>& __rhs)
780 { return __rhs < __lhs; }
782 template<typename _Clock, typename _Dur1, typename _Dur2>
784 operator>=(const time_point<_Clock, _Dur1>& __lhs,
785 const time_point<_Clock, _Dur2>& __rhs)
786 { return !(__lhs < __rhs); }
791 // Why nanosecond resolution as the default?
792 // Why have std::system_clock always count in the highest
793 // resolution (ie nanoseconds), even if on some OSes the low 3
794 // or 9 decimal digits will be always zero? This allows later
795 // implementations to change the system_clock::now()
796 // implementation any time to provide better resolution without
797 // changing function signature or units.
799 // To support the (forward) evolution of the library's defined
800 // clocks, wrap inside inline namespace so that the current
801 // defintions of system_clock, steady_clock, and
802 // high_resolution_clock types are uniquely mangled. This way, new
803 // code can use the latests clocks, while the library can contain
804 // compatibility definitions for previous versions. At some
805 // point, when these clocks settle down, the inlined namespaces
806 // can be removed. XXX GLIBCXX_ABI Deprecated
807 inline namespace _V2 {
810 * @brief System clock.
812 * Time returned represents wall time from the system-wide clock.
816 typedef chrono::nanoseconds duration;
817 typedef duration::rep rep;
818 typedef duration::period period;
819 typedef chrono::time_point<system_clock, duration> time_point;
821 static_assert(system_clock::duration::min()
822 < system_clock::duration::zero(),
823 "a clock's minimum duration cannot be less than its epoch");
825 static constexpr bool is_steady = false;
832 to_time_t(const time_point& __t) noexcept
834 return std::time_t(duration_cast<chrono::seconds>
835 (__t.time_since_epoch()).count());
839 from_time_t(std::time_t __t) noexcept
841 typedef chrono::time_point<system_clock, seconds> __from;
842 return time_point_cast<system_clock::duration>
843 (__from(chrono::seconds(__t)));
849 * @brief Monotonic clock
851 * Time returned has the property of only increasing at a uniform rate.
855 typedef chrono::nanoseconds duration;
856 typedef duration::rep rep;
857 typedef duration::period period;
858 typedef chrono::time_point<steady_clock, duration> time_point;
860 static constexpr bool is_steady = true;
868 * @brief Highest-resolution clock
870 * This is the clock "with the shortest tick period." Alias to
871 * std::system_clock until higher-than-nanosecond definitions
874 using high_resolution_clock = system_clock;
876 } // end inline namespace _V2
877 } // namespace chrono
879 #if __cplusplus > 201103L
881 #define __cpp_lib_chrono_udls 201304
883 inline namespace literals
885 inline namespace chrono_literals
887 template<typename _Rep, unsigned long long _Val>
888 struct _Checked_integral_constant
889 : integral_constant<_Rep, static_cast<_Rep>(_Val)>
891 static_assert(_Checked_integral_constant::value >= 0
892 && _Checked_integral_constant::value == _Val,
893 "literal value cannot be represented by duration type");
896 template<typename _Dur, char... _Digits>
897 constexpr _Dur __check_overflow()
899 using _Val = __parse_int::_Parse_int<_Digits...>;
900 using _Rep = typename _Dur::rep;
901 // TODO: should be simply integral_constant<_Rep, _Val::value>
902 // but GCC doesn't reject narrowing conversions to _Rep.
903 using _CheckedVal = _Checked_integral_constant<_Rep, _Val::value>;
904 return _Dur{_CheckedVal::value};
907 constexpr chrono::duration<long double, ratio<3600,1>>
908 operator""h(long double __hours)
909 { return chrono::duration<long double, ratio<3600,1>>{__hours}; }
911 template <char... _Digits>
912 constexpr chrono::hours
914 { return __check_overflow<chrono::hours, _Digits...>(); }
916 constexpr chrono::duration<long double, ratio<60,1>>
917 operator""min(long double __mins)
918 { return chrono::duration<long double, ratio<60,1>>{__mins}; }
920 template <char... _Digits>
921 constexpr chrono::minutes
923 { return __check_overflow<chrono::minutes, _Digits...>(); }
925 constexpr chrono::duration<long double>
926 operator""s(long double __secs)
927 { return chrono::duration<long double>{__secs}; }
929 template <char... _Digits>
930 constexpr chrono::seconds
932 { return __check_overflow<chrono::seconds, _Digits...>(); }
934 constexpr chrono::duration<long double, milli>
935 operator""ms(long double __msecs)
936 { return chrono::duration<long double, milli>{__msecs}; }
938 template <char... _Digits>
939 constexpr chrono::milliseconds
941 { return __check_overflow<chrono::milliseconds, _Digits...>(); }
943 constexpr chrono::duration<long double, micro>
944 operator""us(long double __usecs)
945 { return chrono::duration<long double, micro>{__usecs}; }
947 template <char... _Digits>
948 constexpr chrono::microseconds
950 { return __check_overflow<chrono::microseconds, _Digits...>(); }
952 constexpr chrono::duration<long double, nano>
953 operator""ns(long double __nsecs)
954 { return chrono::duration<long double, nano>{__nsecs}; }
956 template <char... _Digits>
957 constexpr chrono::nanoseconds
959 { return __check_overflow<chrono::nanoseconds, _Digits...>(); }
961 } // inline namespace chrono_literals
962 } // inline namespace literals
966 using namespace literals::chrono_literals;
967 } // namespace chrono
969 #endif // __cplusplus > 201103L
973 _GLIBCXX_END_NAMESPACE_VERSION
976 #endif //_GLIBCXX_USE_C99_STDINT_TR1
980 #endif //_GLIBCXX_CHRONO