libstdc++
chrono
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1 // <chrono> -*- C++ -*-
2 
3 // Copyright (C) 2008-2018 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/chrono
26  * This is a Standard C++ Library header.
27  */
28 
29 #ifndef _GLIBCXX_CHRONO
30 #define _GLIBCXX_CHRONO 1
31 
32 #pragma GCC system_header
33 
34 #if __cplusplus < 201103L
35 # include <bits/c++0x_warning.h>
36 #else
37 
38 #include <ratio>
39 #include <type_traits>
40 #include <limits>
41 #include <ctime>
42 #include <bits/parse_numbers.h> // for literals support.
43 
44 #ifdef _GLIBCXX_USE_C99_STDINT_TR1
45 
46 namespace std _GLIBCXX_VISIBILITY(default)
47 {
48 _GLIBCXX_BEGIN_NAMESPACE_VERSION
49 
50  /**
51  * @defgroup chrono Time
52  * @ingroup utilities
53  *
54  * Classes and functions for time.
55  * @{
56  */
57 
58  /** @namespace std::chrono
59  * @brief ISO C++ 2011 entities sub-namespace for time and date.
60  */
61  namespace chrono
62  {
63  template<typename _Rep, typename _Period = ratio<1>>
64  struct duration;
65 
66  template<typename _Clock, typename _Dur = typename _Clock::duration>
67  struct time_point;
68  }
69 
70  // 20.11.4.3 specialization of common_type (for duration, sfinae-friendly)
71 
72  template<typename _CT, typename _Period1, typename _Period2>
73  struct __duration_common_type_wrapper
74  {
75  private:
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;
81  public:
82  typedef __success_type<chrono::duration<__cr, __r>> type;
83  };
84 
85  template<typename _Period1, typename _Period2>
86  struct __duration_common_type_wrapper<__failure_type, _Period1, _Period2>
87  { typedef __failure_type type; };
88 
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
94  { };
95 
96  // 20.11.4.3 specialization of common_type (for time_point, sfinae-friendly)
97 
98  template<typename _CT, typename _Clock>
99  struct __timepoint_common_type_wrapper
100  {
101  typedef __success_type<chrono::time_point<_Clock, typename _CT::type>>
102  type;
103  };
104 
105  template<typename _Clock>
106  struct __timepoint_common_type_wrapper<__failure_type, _Clock>
107  { typedef __failure_type type; };
108 
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
114  { };
115 
116  namespace chrono
117  {
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
122  {
123  template<typename _Rep, typename _Period>
124  static constexpr _ToDur
125  __cast(const duration<_Rep, _Period>& __d)
126  {
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)));
131  }
132  };
133 
134  template<typename _ToDur, typename _CF, typename _CR>
135  struct __duration_cast_impl<_ToDur, _CF, _CR, true, true>
136  {
137  template<typename _Rep, typename _Period>
138  static constexpr _ToDur
139  __cast(const duration<_Rep, _Period>& __d)
140  {
141  typedef typename _ToDur::rep __to_rep;
142  return _ToDur(static_cast<__to_rep>(__d.count()));
143  }
144  };
145 
146  template<typename _ToDur, typename _CF, typename _CR>
147  struct __duration_cast_impl<_ToDur, _CF, _CR, true, false>
148  {
149  template<typename _Rep, typename _Period>
150  static constexpr _ToDur
151  __cast(const duration<_Rep, _Period>& __d)
152  {
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)));
156  }
157  };
158 
159  template<typename _ToDur, typename _CF, typename _CR>
160  struct __duration_cast_impl<_ToDur, _CF, _CR, false, true>
161  {
162  template<typename _Rep, typename _Period>
163  static constexpr _ToDur
164  __cast(const duration<_Rep, _Period>& __d)
165  {
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)));
169  }
170  };
171 
172  template<typename _Tp>
173  struct __is_duration
174  : std::false_type
175  { };
176 
177  template<typename _Rep, typename _Period>
178  struct __is_duration<duration<_Rep, _Period>>
179  : std::true_type
180  { };
181 
182  template<typename _Tp>
183  using __enable_if_is_duration
184  = typename enable_if<__is_duration<_Tp>::value, _Tp>::type;
185 
186  template<typename _Tp>
187  using __disable_if_is_duration
188  = typename enable_if<!__is_duration<_Tp>::value, _Tp>::type;
189 
190  /// duration_cast
191  template<typename _ToDur, typename _Rep, typename _Period>
192  constexpr __enable_if_is_duration<_ToDur>
193  duration_cast(const duration<_Rep, _Period>& __d)
194  {
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
199  __cr;
200  typedef __duration_cast_impl<_ToDur, __cf, __cr,
201  __cf::num == 1, __cf::den == 1> __dc;
202  return __dc::__cast(__d);
203  }
204 
205  /// treat_as_floating_point
206  template<typename _Rep>
207  struct treat_as_floating_point
208  : is_floating_point<_Rep>
209  { };
210 
211 #if __cplusplus > 201402L
212  template <typename _Rep>
213  inline constexpr bool treat_as_floating_point_v =
214  treat_as_floating_point<_Rep>::value;
215 #endif // C++17
216 
217 #if __cplusplus >= 201703L
218 # define __cpp_lib_chrono 201611
219 
220  template<typename _ToDur, typename _Rep, typename _Period>
221  constexpr __enable_if_is_duration<_ToDur>
222  floor(const duration<_Rep, _Period>& __d)
223  {
224  auto __to = chrono::duration_cast<_ToDur>(__d);
225  if (__to > __d)
226  return __to - _ToDur{1};
227  return __to;
228  }
229 
230  template<typename _ToDur, typename _Rep, typename _Period>
231  constexpr __enable_if_is_duration<_ToDur>
232  ceil(const duration<_Rep, _Period>& __d)
233  {
234  auto __to = chrono::duration_cast<_ToDur>(__d);
235  if (__to < __d)
236  return __to + _ToDur{1};
237  return __to;
238  }
239 
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,
244  _ToDur>
245  round(const duration<_Rep, _Period>& __d)
246  {
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)
252  {
253  if (__t0.count() & 1)
254  return __t1;
255  return __t0;
256  }
257  else if (__diff0 < __diff1)
258  return __t0;
259  return __t1;
260  }
261 
262  template<typename _Rep, typename _Period>
263  constexpr
264  enable_if_t<numeric_limits<_Rep>::is_signed, duration<_Rep, _Period>>
265  abs(duration<_Rep, _Period> __d)
266  {
267  if (__d >= __d.zero())
268  return __d;
269  return -__d;
270  }
271 #endif // C++17
272 
273  /// duration_values
274  template<typename _Rep>
275  struct duration_values
276  {
277  static constexpr _Rep
278  zero() noexcept
279  { return _Rep(0); }
280 
281  static constexpr _Rep
282  max() noexcept
283  { return numeric_limits<_Rep>::max(); }
284 
285  static constexpr _Rep
286  min() noexcept
287  { return numeric_limits<_Rep>::lowest(); }
288  };
289 
290  template<typename _Tp>
291  struct __is_ratio
292  : std::false_type
293  { };
294 
295  template<intmax_t _Num, intmax_t _Den>
296  struct __is_ratio<ratio<_Num, _Den>>
297  : std::true_type
298  { };
299 
300  /// duration
301  template<typename _Rep, typename _Period>
302  struct duration
303  {
304  private:
305  template<typename _Rep2>
306  using __is_float = treat_as_floating_point<_Rep2>;
307 
308  // _Period2 is an exact multiple of _Period
309  template<typename _Period2>
310  using __is_harmonic
311  = __bool_constant<ratio_divide<_Period2, _Period>::den == 1>;
312 
313  public:
314 
315  typedef _Rep rep;
316  typedef _Period period;
317 
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");
322 
323  // 20.11.5.1 construction / copy / destroy
324  constexpr duration() = default;
325 
326  duration(const duration&) = default;
327 
328  // _GLIBCXX_RESOLVE_LIB_DEFECTS
329  // 3050. Conversion specification problem in chrono::duration
330  template<typename _Rep2, typename = _Require<
331  is_convertible<const _Rep2&, rep>,
332  __or_<__is_float<rep>, __not_<__is_float<_Rep2>>>>>
333  constexpr explicit duration(const _Rep2& __rep)
334  : __r(static_cast<rep>(__rep)) { }
335 
336  template<typename _Rep2, typename _Period2, typename = _Require<
337  __or_<__is_float<rep>,
338  __and_<__is_harmonic<_Period2>,
339  __not_<__is_float<_Rep2>>>>>>
340  constexpr duration(const duration<_Rep2, _Period2>& __d)
341  : __r(duration_cast<duration>(__d).count()) { }
342 
343  ~duration() = default;
344  duration& operator=(const duration&) = default;
345 
346  // 20.11.5.2 observer
347  constexpr rep
348  count() const
349  { return __r; }
350 
351  // 20.11.5.3 arithmetic
352  constexpr duration
353  operator+() const
354  { return *this; }
355 
356  constexpr duration
357  operator-() const
358  { return duration(-__r); }
359 
360  _GLIBCXX17_CONSTEXPR duration&
361  operator++()
362  {
363  ++__r;
364  return *this;
365  }
366 
367  _GLIBCXX17_CONSTEXPR duration
368  operator++(int)
369  { return duration(__r++); }
370 
371  _GLIBCXX17_CONSTEXPR duration&
372  operator--()
373  {
374  --__r;
375  return *this;
376  }
377 
378  _GLIBCXX17_CONSTEXPR duration
379  operator--(int)
380  { return duration(__r--); }
381 
382  _GLIBCXX17_CONSTEXPR duration&
383  operator+=(const duration& __d)
384  {
385  __r += __d.count();
386  return *this;
387  }
388 
389  _GLIBCXX17_CONSTEXPR duration&
390  operator-=(const duration& __d)
391  {
392  __r -= __d.count();
393  return *this;
394  }
395 
396  _GLIBCXX17_CONSTEXPR duration&
397  operator*=(const rep& __rhs)
398  {
399  __r *= __rhs;
400  return *this;
401  }
402 
403  _GLIBCXX17_CONSTEXPR duration&
404  operator/=(const rep& __rhs)
405  {
406  __r /= __rhs;
407  return *this;
408  }
409 
410  // DR 934.
411  template<typename _Rep2 = rep>
412  _GLIBCXX17_CONSTEXPR
413  typename enable_if<!treat_as_floating_point<_Rep2>::value,
414  duration&>::type
415  operator%=(const rep& __rhs)
416  {
417  __r %= __rhs;
418  return *this;
419  }
420 
421  template<typename _Rep2 = rep>
422  _GLIBCXX17_CONSTEXPR
423  typename enable_if<!treat_as_floating_point<_Rep2>::value,
424  duration&>::type
425  operator%=(const duration& __d)
426  {
427  __r %= __d.count();
428  return *this;
429  }
430 
431  // 20.11.5.4 special values
432  static constexpr duration
433  zero() noexcept
434  { return duration(duration_values<rep>::zero()); }
435 
436  static constexpr duration
437  min() noexcept
438  { return duration(duration_values<rep>::min()); }
439 
440  static constexpr duration
441  max() noexcept
442  { return duration(duration_values<rep>::max()); }
443 
444  private:
445  rep __r;
446  };
447 
448  template<typename _Rep1, typename _Period1,
449  typename _Rep2, typename _Period2>
450  constexpr typename common_type<duration<_Rep1, _Period1>,
451  duration<_Rep2, _Period2>>::type
452  operator+(const duration<_Rep1, _Period1>& __lhs,
453  const duration<_Rep2, _Period2>& __rhs)
454  {
455  typedef duration<_Rep1, _Period1> __dur1;
456  typedef duration<_Rep2, _Period2> __dur2;
457  typedef typename common_type<__dur1,__dur2>::type __cd;
458  return __cd(__cd(__lhs).count() + __cd(__rhs).count());
459  }
460 
461  template<typename _Rep1, typename _Period1,
462  typename _Rep2, typename _Period2>
463  constexpr typename common_type<duration<_Rep1, _Period1>,
464  duration<_Rep2, _Period2>>::type
465  operator-(const duration<_Rep1, _Period1>& __lhs,
466  const duration<_Rep2, _Period2>& __rhs)
467  {
468  typedef duration<_Rep1, _Period1> __dur1;
469  typedef duration<_Rep2, _Period2> __dur2;
470  typedef typename common_type<__dur1,__dur2>::type __cd;
471  return __cd(__cd(__lhs).count() - __cd(__rhs).count());
472  }
473 
474  // SFINAE helper to obtain common_type<_Rep1, _Rep2> only if _Rep2
475  // is implicitly convertible to it.
476  // _GLIBCXX_RESOLVE_LIB_DEFECTS
477  // 3050. Conversion specification problem in chrono::duration constructor
478  template<typename _Rep1, typename _Rep2,
479  typename _CRep = typename common_type<_Rep1, _Rep2>::type>
480  using __common_rep_t = typename
481  enable_if<is_convertible<const _Rep2&, _CRep>::value, _CRep>::type;
482 
483  template<typename _Rep1, typename _Period, typename _Rep2>
484  constexpr duration<__common_rep_t<_Rep1, _Rep2>, _Period>
485  operator*(const duration<_Rep1, _Period>& __d, const _Rep2& __s)
486  {
487  typedef duration<typename common_type<_Rep1, _Rep2>::type, _Period>
488  __cd;
489  return __cd(__cd(__d).count() * __s);
490  }
491 
492  template<typename _Rep1, typename _Rep2, typename _Period>
493  constexpr duration<__common_rep_t<_Rep2, _Rep1>, _Period>
494  operator*(const _Rep1& __s, const duration<_Rep2, _Period>& __d)
495  { return __d * __s; }
496 
497  template<typename _Rep1, typename _Period, typename _Rep2>
498  constexpr
499  duration<__common_rep_t<_Rep1, __disable_if_is_duration<_Rep2>>, _Period>
500  operator/(const duration<_Rep1, _Period>& __d, const _Rep2& __s)
501  {
502  typedef duration<typename common_type<_Rep1, _Rep2>::type, _Period>
503  __cd;
504  return __cd(__cd(__d).count() / __s);
505  }
506 
507  template<typename _Rep1, typename _Period1,
508  typename _Rep2, typename _Period2>
509  constexpr typename common_type<_Rep1, _Rep2>::type
510  operator/(const duration<_Rep1, _Period1>& __lhs,
511  const duration<_Rep2, _Period2>& __rhs)
512  {
513  typedef duration<_Rep1, _Period1> __dur1;
514  typedef duration<_Rep2, _Period2> __dur2;
515  typedef typename common_type<__dur1,__dur2>::type __cd;
516  return __cd(__lhs).count() / __cd(__rhs).count();
517  }
518 
519  // DR 934.
520  template<typename _Rep1, typename _Period, typename _Rep2>
521  constexpr
522  duration<__common_rep_t<_Rep1, __disable_if_is_duration<_Rep2>>, _Period>
523  operator%(const duration<_Rep1, _Period>& __d, const _Rep2& __s)
524  {
525  typedef duration<typename common_type<_Rep1, _Rep2>::type, _Period>
526  __cd;
527  return __cd(__cd(__d).count() % __s);
528  }
529 
530  template<typename _Rep1, typename _Period1,
531  typename _Rep2, typename _Period2>
532  constexpr typename common_type<duration<_Rep1, _Period1>,
533  duration<_Rep2, _Period2>>::type
534  operator%(const duration<_Rep1, _Period1>& __lhs,
535  const duration<_Rep2, _Period2>& __rhs)
536  {
537  typedef duration<_Rep1, _Period1> __dur1;
538  typedef duration<_Rep2, _Period2> __dur2;
539  typedef typename common_type<__dur1,__dur2>::type __cd;
540  return __cd(__cd(__lhs).count() % __cd(__rhs).count());
541  }
542 
543  // comparisons
544  template<typename _Rep1, typename _Period1,
545  typename _Rep2, typename _Period2>
546  constexpr bool
547  operator==(const duration<_Rep1, _Period1>& __lhs,
548  const duration<_Rep2, _Period2>& __rhs)
549  {
550  typedef duration<_Rep1, _Period1> __dur1;
551  typedef duration<_Rep2, _Period2> __dur2;
552  typedef typename common_type<__dur1,__dur2>::type __ct;
553  return __ct(__lhs).count() == __ct(__rhs).count();
554  }
555 
556  template<typename _Rep1, typename _Period1,
557  typename _Rep2, typename _Period2>
558  constexpr bool
559  operator<(const duration<_Rep1, _Period1>& __lhs,
560  const duration<_Rep2, _Period2>& __rhs)
561  {
562  typedef duration<_Rep1, _Period1> __dur1;
563  typedef duration<_Rep2, _Period2> __dur2;
564  typedef typename common_type<__dur1,__dur2>::type __ct;
565  return __ct(__lhs).count() < __ct(__rhs).count();
566  }
567 
568  template<typename _Rep1, typename _Period1,
569  typename _Rep2, typename _Period2>
570  constexpr bool
571  operator!=(const duration<_Rep1, _Period1>& __lhs,
572  const duration<_Rep2, _Period2>& __rhs)
573  { return !(__lhs == __rhs); }
574 
575  template<typename _Rep1, typename _Period1,
576  typename _Rep2, typename _Period2>
577  constexpr bool
578  operator<=(const duration<_Rep1, _Period1>& __lhs,
579  const duration<_Rep2, _Period2>& __rhs)
580  { return !(__rhs < __lhs); }
581 
582  template<typename _Rep1, typename _Period1,
583  typename _Rep2, typename _Period2>
584  constexpr bool
585  operator>(const duration<_Rep1, _Period1>& __lhs,
586  const duration<_Rep2, _Period2>& __rhs)
587  { return __rhs < __lhs; }
588 
589  template<typename _Rep1, typename _Period1,
590  typename _Rep2, typename _Period2>
591  constexpr bool
592  operator>=(const duration<_Rep1, _Period1>& __lhs,
593  const duration<_Rep2, _Period2>& __rhs)
594  { return !(__lhs < __rhs); }
595 
596  /// nanoseconds
597  typedef duration<int64_t, nano> nanoseconds;
598 
599  /// microseconds
600  typedef duration<int64_t, micro> microseconds;
601 
602  /// milliseconds
603  typedef duration<int64_t, milli> milliseconds;
604 
605  /// seconds
606  typedef duration<int64_t> seconds;
607 
608  /// minutes
609  typedef duration<int64_t, ratio< 60>> minutes;
610 
611  /// hours
612  typedef duration<int64_t, ratio<3600>> hours;
613 
614  /// time_point
615  template<typename _Clock, typename _Dur>
616  struct time_point
617  {
618  typedef _Clock clock;
619  typedef _Dur duration;
620  typedef typename duration::rep rep;
621  typedef typename duration::period period;
622 
623  constexpr time_point() : __d(duration::zero())
624  { }
625 
626  constexpr explicit time_point(const duration& __dur)
627  : __d(__dur)
628  { }
629 
630  // conversions
631  template<typename _Dur2,
632  typename = _Require<is_convertible<_Dur2, _Dur>>>
633  constexpr time_point(const time_point<clock, _Dur2>& __t)
634  : __d(__t.time_since_epoch())
635  { }
636 
637  // observer
638  constexpr duration
639  time_since_epoch() const
640  { return __d; }
641 
642  // arithmetic
643  _GLIBCXX17_CONSTEXPR time_point&
644  operator+=(const duration& __dur)
645  {
646  __d += __dur;
647  return *this;
648  }
649 
650  _GLIBCXX17_CONSTEXPR time_point&
651  operator-=(const duration& __dur)
652  {
653  __d -= __dur;
654  return *this;
655  }
656 
657  // special values
658  static constexpr time_point
659  min() noexcept
660  { return time_point(duration::min()); }
661 
662  static constexpr time_point
663  max() noexcept
664  { return time_point(duration::max()); }
665 
666  private:
667  duration __d;
668  };
669 
670  /// time_point_cast
671  template<typename _ToDur, typename _Clock, typename _Dur>
672  constexpr typename enable_if<__is_duration<_ToDur>::value,
673  time_point<_Clock, _ToDur>>::type
674  time_point_cast(const time_point<_Clock, _Dur>& __t)
675  {
676  typedef time_point<_Clock, _ToDur> __time_point;
677  return __time_point(duration_cast<_ToDur>(__t.time_since_epoch()));
678  }
679 
680 #if __cplusplus > 201402L
681  template<typename _ToDur, typename _Clock, typename _Dur>
682  constexpr
683  enable_if_t<__is_duration<_ToDur>::value, time_point<_Clock, _ToDur>>
684  floor(const time_point<_Clock, _Dur>& __tp)
685  {
686  return time_point<_Clock, _ToDur>{
687  chrono::floor<_ToDur>(__tp.time_since_epoch())};
688  }
689 
690  template<typename _ToDur, typename _Clock, typename _Dur>
691  constexpr
692  enable_if_t<__is_duration<_ToDur>::value, time_point<_Clock, _ToDur>>
693  ceil(const time_point<_Clock, _Dur>& __tp)
694  {
695  return time_point<_Clock, _ToDur>{
696  chrono::ceil<_ToDur>(__tp.time_since_epoch())};
697  }
698 
699  template<typename _ToDur, typename _Clock, typename _Dur>
700  constexpr enable_if_t<
701  __and_<__is_duration<_ToDur>,
702  __not_<treat_as_floating_point<typename _ToDur::rep>>>::value,
703  time_point<_Clock, _ToDur>>
704  round(const time_point<_Clock, _Dur>& __tp)
705  {
706  return time_point<_Clock, _ToDur>{
707  chrono::round<_ToDur>(__tp.time_since_epoch())};
708  }
709 #endif // C++17
710 
711  template<typename _Clock, typename _Dur1,
712  typename _Rep2, typename _Period2>
713  constexpr time_point<_Clock,
714  typename common_type<_Dur1, duration<_Rep2, _Period2>>::type>
715  operator+(const time_point<_Clock, _Dur1>& __lhs,
716  const duration<_Rep2, _Period2>& __rhs)
717  {
718  typedef duration<_Rep2, _Period2> __dur2;
719  typedef typename common_type<_Dur1,__dur2>::type __ct;
720  typedef time_point<_Clock, __ct> __time_point;
721  return __time_point(__lhs.time_since_epoch() + __rhs);
722  }
723 
724  template<typename _Rep1, typename _Period1,
725  typename _Clock, typename _Dur2>
726  constexpr time_point<_Clock,
727  typename common_type<duration<_Rep1, _Period1>, _Dur2>::type>
728  operator+(const duration<_Rep1, _Period1>& __lhs,
729  const time_point<_Clock, _Dur2>& __rhs)
730  {
731  typedef duration<_Rep1, _Period1> __dur1;
732  typedef typename common_type<__dur1,_Dur2>::type __ct;
733  typedef time_point<_Clock, __ct> __time_point;
734  return __time_point(__rhs.time_since_epoch() + __lhs);
735  }
736 
737  template<typename _Clock, typename _Dur1,
738  typename _Rep2, typename _Period2>
739  constexpr time_point<_Clock,
740  typename common_type<_Dur1, duration<_Rep2, _Period2>>::type>
741  operator-(const time_point<_Clock, _Dur1>& __lhs,
742  const duration<_Rep2, _Period2>& __rhs)
743  {
744  typedef duration<_Rep2, _Period2> __dur2;
745  typedef typename common_type<_Dur1,__dur2>::type __ct;
746  typedef time_point<_Clock, __ct> __time_point;
747  return __time_point(__lhs.time_since_epoch() -__rhs);
748  }
749 
750  template<typename _Clock, typename _Dur1, typename _Dur2>
751  constexpr typename common_type<_Dur1, _Dur2>::type
752  operator-(const time_point<_Clock, _Dur1>& __lhs,
753  const time_point<_Clock, _Dur2>& __rhs)
754  { return __lhs.time_since_epoch() - __rhs.time_since_epoch(); }
755 
756  template<typename _Clock, typename _Dur1, typename _Dur2>
757  constexpr bool
758  operator==(const time_point<_Clock, _Dur1>& __lhs,
759  const time_point<_Clock, _Dur2>& __rhs)
760  { return __lhs.time_since_epoch() == __rhs.time_since_epoch(); }
761 
762  template<typename _Clock, typename _Dur1, typename _Dur2>
763  constexpr bool
764  operator!=(const time_point<_Clock, _Dur1>& __lhs,
765  const time_point<_Clock, _Dur2>& __rhs)
766  { return !(__lhs == __rhs); }
767 
768  template<typename _Clock, typename _Dur1, typename _Dur2>
769  constexpr bool
770  operator<(const time_point<_Clock, _Dur1>& __lhs,
771  const time_point<_Clock, _Dur2>& __rhs)
772  { return __lhs.time_since_epoch() < __rhs.time_since_epoch(); }
773 
774  template<typename _Clock, typename _Dur1, typename _Dur2>
775  constexpr bool
776  operator<=(const time_point<_Clock, _Dur1>& __lhs,
777  const time_point<_Clock, _Dur2>& __rhs)
778  { return !(__rhs < __lhs); }
779 
780  template<typename _Clock, typename _Dur1, typename _Dur2>
781  constexpr bool
782  operator>(const time_point<_Clock, _Dur1>& __lhs,
783  const time_point<_Clock, _Dur2>& __rhs)
784  { return __rhs < __lhs; }
785 
786  template<typename _Clock, typename _Dur1, typename _Dur2>
787  constexpr bool
788  operator>=(const time_point<_Clock, _Dur1>& __lhs,
789  const time_point<_Clock, _Dur2>& __rhs)
790  { return !(__lhs < __rhs); }
791 
792 
793  // Clocks.
794 
795  // Why nanosecond resolution as the default?
796  // Why have std::system_clock always count in the highest
797  // resolution (ie nanoseconds), even if on some OSes the low 3
798  // or 9 decimal digits will be always zero? This allows later
799  // implementations to change the system_clock::now()
800  // implementation any time to provide better resolution without
801  // changing function signature or units.
802 
803  // To support the (forward) evolution of the library's defined
804  // clocks, wrap inside inline namespace so that the current
805  // defintions of system_clock, steady_clock, and
806  // high_resolution_clock types are uniquely mangled. This way, new
807  // code can use the latests clocks, while the library can contain
808  // compatibility definitions for previous versions. At some
809  // point, when these clocks settle down, the inlined namespaces
810  // can be removed. XXX GLIBCXX_ABI Deprecated
811  inline namespace _V2 {
812 
813  /**
814  * @brief System clock.
815  *
816  * Time returned represents wall time from the system-wide clock.
817  */
818  struct system_clock
819  {
820  typedef chrono::nanoseconds duration;
821  typedef duration::rep rep;
822  typedef duration::period period;
823  typedef chrono::time_point<system_clock, duration> time_point;
824 
825  static_assert(system_clock::duration::min()
826  < system_clock::duration::zero(),
827  "a clock's minimum duration cannot be less than its epoch");
828 
829  static constexpr bool is_steady = false;
830 
831  static time_point
832  now() noexcept;
833 
834  // Map to C API
835  static std::time_t
836  to_time_t(const time_point& __t) noexcept
837  {
838  return std::time_t(duration_cast<chrono::seconds>
839  (__t.time_since_epoch()).count());
840  }
841 
842  static time_point
843  from_time_t(std::time_t __t) noexcept
844  {
845  typedef chrono::time_point<system_clock, seconds> __from;
846  return time_point_cast<system_clock::duration>
847  (__from(chrono::seconds(__t)));
848  }
849  };
850 
851 
852  /**
853  * @brief Monotonic clock
854  *
855  * Time returned has the property of only increasing at a uniform rate.
856  */
857  struct steady_clock
858  {
859  typedef chrono::nanoseconds duration;
860  typedef duration::rep rep;
861  typedef duration::period period;
862  typedef chrono::time_point<steady_clock, duration> time_point;
863 
864  static constexpr bool is_steady = true;
865 
866  static time_point
867  now() noexcept;
868  };
869 
870 
871  /**
872  * @brief Highest-resolution clock
873  *
874  * This is the clock "with the shortest tick period." Alias to
875  * std::system_clock until higher-than-nanosecond definitions
876  * become feasible.
877  */
878  using high_resolution_clock = system_clock;
879 
880  } // end inline namespace _V2
881  } // namespace chrono
882 
883 #if __cplusplus > 201103L
884 
885 #define __cpp_lib_chrono_udls 201304
886 
887  inline namespace literals
888  {
889  inline namespace chrono_literals
890  {
891 #pragma GCC diagnostic push
892 #pragma GCC diagnostic ignored "-Wliteral-suffix"
893  template<typename _Rep, unsigned long long _Val>
894  struct _Checked_integral_constant
895  : integral_constant<_Rep, static_cast<_Rep>(_Val)>
896  {
897  static_assert(_Checked_integral_constant::value >= 0
898  && _Checked_integral_constant::value == _Val,
899  "literal value cannot be represented by duration type");
900  };
901 
902  template<typename _Dur, char... _Digits>
903  constexpr _Dur __check_overflow()
904  {
905  using _Val = __parse_int::_Parse_int<_Digits...>;
906  using _Rep = typename _Dur::rep;
907  // TODO: should be simply integral_constant<_Rep, _Val::value>
908  // but GCC doesn't reject narrowing conversions to _Rep.
909  using _CheckedVal = _Checked_integral_constant<_Rep, _Val::value>;
910  return _Dur{_CheckedVal::value};
911  }
912 
913  constexpr chrono::duration<long double, ratio<3600,1>>
914  operator""h(long double __hours)
915  { return chrono::duration<long double, ratio<3600,1>>{__hours}; }
916 
917  template <char... _Digits>
918  constexpr chrono::hours
919  operator""h()
920  { return __check_overflow<chrono::hours, _Digits...>(); }
921 
922  constexpr chrono::duration<long double, ratio<60,1>>
923  operator""min(long double __mins)
924  { return chrono::duration<long double, ratio<60,1>>{__mins}; }
925 
926  template <char... _Digits>
927  constexpr chrono::minutes
928  operator""min()
929  { return __check_overflow<chrono::minutes, _Digits...>(); }
930 
931  constexpr chrono::duration<long double>
932  operator""s(long double __secs)
933  { return chrono::duration<long double>{__secs}; }
934 
935  template <char... _Digits>
936  constexpr chrono::seconds
937  operator""s()
938  { return __check_overflow<chrono::seconds, _Digits...>(); }
939 
940  constexpr chrono::duration<long double, milli>
941  operator""ms(long double __msecs)
942  { return chrono::duration<long double, milli>{__msecs}; }
943 
944  template <char... _Digits>
945  constexpr chrono::milliseconds
946  operator""ms()
947  { return __check_overflow<chrono::milliseconds, _Digits...>(); }
948 
949  constexpr chrono::duration<long double, micro>
950  operator""us(long double __usecs)
951  { return chrono::duration<long double, micro>{__usecs}; }
952 
953  template <char... _Digits>
954  constexpr chrono::microseconds
955  operator""us()
956  { return __check_overflow<chrono::microseconds, _Digits...>(); }
957 
958  constexpr chrono::duration<long double, nano>
959  operator""ns(long double __nsecs)
960  { return chrono::duration<long double, nano>{__nsecs}; }
961 
962  template <char... _Digits>
963  constexpr chrono::nanoseconds
964  operator""ns()
965  { return __check_overflow<chrono::nanoseconds, _Digits...>(); }
966 
967 #pragma GCC diagnostic pop
968  } // inline namespace chrono_literals
969  } // inline namespace literals
970 
971  namespace chrono
972  {
973  using namespace literals::chrono_literals;
974  } // namespace chrono
975 
976 #endif // C++14
977 
978  // @} group chrono
979 
980 _GLIBCXX_END_NAMESPACE_VERSION
981 } // namespace std
982 
983 #endif //_GLIBCXX_USE_C99_STDINT_TR1
984 
985 #endif // C++11
986 
987 #endif //_GLIBCXX_CHRONO