libstdc++
chrono
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1 // <chrono> -*- C++ -*-
2 
3 // Copyright (C) 2008-2017 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  /**
49  * @defgroup chrono Time
50  * @ingroup utilities
51  *
52  * Classes and functions for time.
53  * @{
54  */
55 
56  /** @namespace std::chrono
57  * @brief ISO C++ 2011 entities sub-namespace for time and date.
58  */
59  namespace chrono
60  {
61  _GLIBCXX_BEGIN_NAMESPACE_VERSION
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  _GLIBCXX_END_NAMESPACE_VERSION
70  }
71 
72 _GLIBCXX_BEGIN_NAMESPACE_VERSION
73 
74  // 20.11.4.3 specialization of common_type (for duration, sfinae-friendly)
75 
76  template<typename _CT, typename _Period1, typename _Period2>
77  struct __duration_common_type_wrapper
78  {
79  private:
80  typedef __static_gcd<_Period1::num, _Period2::num> __gcd_num;
81  typedef __static_gcd<_Period1::den, _Period2::den> __gcd_den;
82  typedef typename _CT::type __cr;
83  typedef ratio<__gcd_num::value,
84  (_Period1::den / __gcd_den::value) * _Period2::den> __r;
85  public:
86  typedef __success_type<chrono::duration<__cr, __r>> type;
87  };
88 
89  template<typename _Period1, typename _Period2>
90  struct __duration_common_type_wrapper<__failure_type, _Period1, _Period2>
91  { typedef __failure_type type; };
92 
93  template<typename _Rep1, typename _Period1, typename _Rep2, typename _Period2>
94  struct common_type<chrono::duration<_Rep1, _Period1>,
95  chrono::duration<_Rep2, _Period2>>
96  : public __duration_common_type_wrapper<typename __member_type_wrapper<
97  common_type<_Rep1, _Rep2>>::type, _Period1, _Period2>::type
98  { };
99 
100  // 20.11.4.3 specialization of common_type (for time_point, sfinae-friendly)
101 
102  template<typename _CT, typename _Clock>
103  struct __timepoint_common_type_wrapper
104  {
105  typedef __success_type<chrono::time_point<_Clock, typename _CT::type>>
106  type;
107  };
108 
109  template<typename _Clock>
110  struct __timepoint_common_type_wrapper<__failure_type, _Clock>
111  { typedef __failure_type type; };
112 
113  template<typename _Clock, typename _Duration1, typename _Duration2>
114  struct common_type<chrono::time_point<_Clock, _Duration1>,
115  chrono::time_point<_Clock, _Duration2>>
116  : public __timepoint_common_type_wrapper<typename __member_type_wrapper<
117  common_type<_Duration1, _Duration2>>::type, _Clock>::type
118  { };
119 
120 _GLIBCXX_END_NAMESPACE_VERSION
121 
122  namespace chrono
123  {
124  _GLIBCXX_BEGIN_NAMESPACE_VERSION
125 
126  // Primary template for duration_cast impl.
127  template<typename _ToDur, typename _CF, typename _CR,
128  bool _NumIsOne = false, bool _DenIsOne = false>
129  struct __duration_cast_impl
130  {
131  template<typename _Rep, typename _Period>
132  static constexpr _ToDur
133  __cast(const duration<_Rep, _Period>& __d)
134  {
135  typedef typename _ToDur::rep __to_rep;
136  return _ToDur(static_cast<__to_rep>(static_cast<_CR>(__d.count())
137  * static_cast<_CR>(_CF::num)
138  / static_cast<_CR>(_CF::den)));
139  }
140  };
141 
142  template<typename _ToDur, typename _CF, typename _CR>
143  struct __duration_cast_impl<_ToDur, _CF, _CR, true, true>
144  {
145  template<typename _Rep, typename _Period>
146  static constexpr _ToDur
147  __cast(const duration<_Rep, _Period>& __d)
148  {
149  typedef typename _ToDur::rep __to_rep;
150  return _ToDur(static_cast<__to_rep>(__d.count()));
151  }
152  };
153 
154  template<typename _ToDur, typename _CF, typename _CR>
155  struct __duration_cast_impl<_ToDur, _CF, _CR, true, false>
156  {
157  template<typename _Rep, typename _Period>
158  static constexpr _ToDur
159  __cast(const duration<_Rep, _Period>& __d)
160  {
161  typedef typename _ToDur::rep __to_rep;
162  return _ToDur(static_cast<__to_rep>(
163  static_cast<_CR>(__d.count()) / static_cast<_CR>(_CF::den)));
164  }
165  };
166 
167  template<typename _ToDur, typename _CF, typename _CR>
168  struct __duration_cast_impl<_ToDur, _CF, _CR, false, true>
169  {
170  template<typename _Rep, typename _Period>
171  static constexpr _ToDur
172  __cast(const duration<_Rep, _Period>& __d)
173  {
174  typedef typename _ToDur::rep __to_rep;
175  return _ToDur(static_cast<__to_rep>(
176  static_cast<_CR>(__d.count()) * static_cast<_CR>(_CF::num)));
177  }
178  };
179 
180  template<typename _Tp>
181  struct __is_duration
182  : std::false_type
183  { };
184 
185  template<typename _Rep, typename _Period>
186  struct __is_duration<duration<_Rep, _Period>>
187  : std::true_type
188  { };
189 
190  /// duration_cast
191  template<typename _ToDur, typename _Rep, typename _Period>
192  constexpr typename enable_if<__is_duration<_ToDur>::value,
193  _ToDur>::type
194  duration_cast(const duration<_Rep, _Period>& __d)
195  {
196  typedef typename _ToDur::period __to_period;
197  typedef typename _ToDur::rep __to_rep;
198  typedef ratio_divide<_Period, __to_period> __cf;
199  typedef typename common_type<__to_rep, _Rep, intmax_t>::type
200  __cr;
201  typedef __duration_cast_impl<_ToDur, __cf, __cr,
202  __cf::num == 1, __cf::den == 1> __dc;
203  return __dc::__cast(__d);
204  }
205 
206  /// treat_as_floating_point
207  template<typename _Rep>
208  struct treat_as_floating_point
209  : is_floating_point<_Rep>
210  { };
211 
212 #if __cplusplus > 201402L
213  template <typename _Rep>
214  constexpr bool treat_as_floating_point_v =
215  treat_as_floating_point<_Rep>::value;
216 #endif // C++17
217 
218 #if __cplusplus > 201402L
219 # define __cpp_lib_chrono 201510
220 
221  template<typename _ToDur, typename _Rep, typename _Period>
222  constexpr enable_if_t<__is_duration<_ToDur>::value, _ToDur>
223  floor(const duration<_Rep, _Period>& __d)
224  {
225  auto __to = chrono::duration_cast<_ToDur>(__d);
226  if (__to > __d)
227  return __to - _ToDur{1};
228  return __to;
229  }
230 
231  template<typename _ToDur, typename _Rep, typename _Period>
232  constexpr enable_if_t<__is_duration<_ToDur>::value, _ToDur>
233  ceil(const duration<_Rep, _Period>& __d)
234  {
235  auto __to = chrono::duration_cast<_ToDur>(__d);
236  if (__to < __d)
237  return __to + _ToDur{1};
238  return __to;
239  }
240 
241  template <typename _ToDur, typename _Rep, typename _Period>
242  constexpr enable_if_t<
243  __and_<__is_duration<_ToDur>,
244  __not_<treat_as_floating_point<typename _ToDur::rep>>>::value,
245  _ToDur>
246  round(const duration<_Rep, _Period>& __d)
247  {
248  _ToDur __t0 = chrono::floor<_ToDur>(__d);
249  _ToDur __t1 = __t0 + _ToDur{1};
250  auto __diff0 = __d - __t0;
251  auto __diff1 = __t1 - __d;
252  if (__diff0 == __diff1)
253  {
254  if (__t0.count() & 1)
255  return __t1;
256  return __t0;
257  }
258  else if (__diff0 < __diff1)
259  return __t0;
260  return __t1;
261  }
262 
263  template<typename _Rep, typename _Period>
264  constexpr
265  enable_if_t<numeric_limits<_Rep>::is_signed, duration<_Rep, _Period>>
266  abs(duration<_Rep, _Period> __d)
267  {
268  if (__d >= __d.zero())
269  return __d;
270  return -__d;
271  }
272 #endif // C++17
273 
274  /// duration_values
275  template<typename _Rep>
276  struct duration_values
277  {
278  static constexpr _Rep
279  zero()
280  { return _Rep(0); }
281 
282  static constexpr _Rep
283  max()
284  { return numeric_limits<_Rep>::max(); }
285 
286  static constexpr _Rep
287  min()
288  { return numeric_limits<_Rep>::lowest(); }
289  };
290 
291  template<typename _Tp>
292  struct __is_ratio
293  : std::false_type
294  { };
295 
296  template<intmax_t _Num, intmax_t _Den>
297  struct __is_ratio<ratio<_Num, _Den>>
298  : std::true_type
299  { };
300 
301  /// duration
302  template<typename _Rep, typename _Period>
303  struct duration
304  {
305  typedef _Rep rep;
306  typedef _Period period;
307 
308  static_assert(!__is_duration<_Rep>::value, "rep cannot be a duration");
309  static_assert(__is_ratio<_Period>::value,
310  "period must be a specialization of ratio");
311  static_assert(_Period::num > 0, "period must be positive");
312 
313  // 20.11.5.1 construction / copy / destroy
314  constexpr duration() = default;
315 
316  // NB: Make constexpr implicit. This cannot be explicitly
317  // constexpr, as any UDT that is not a literal type with a
318  // constexpr copy constructor will be ill-formed.
319  duration(const duration&) = default;
320 
321  template<typename _Rep2, typename = typename
322  enable_if<is_convertible<_Rep2, rep>::value
323  && (treat_as_floating_point<rep>::value
324  || !treat_as_floating_point<_Rep2>::value)>::type>
325  constexpr explicit duration(const _Rep2& __rep)
326  : __r(static_cast<rep>(__rep)) { }
327 
328  template<typename _Rep2, typename _Period2, typename = typename
329  enable_if<treat_as_floating_point<rep>::value
330  || (ratio_divide<_Period2, period>::den == 1
331  && !treat_as_floating_point<_Rep2>::value)>::type>
332  constexpr duration(const duration<_Rep2, _Period2>& __d)
333  : __r(duration_cast<duration>(__d).count()) { }
334 
335  ~duration() = default;
336  duration& operator=(const duration&) = default;
337 
338  // 20.11.5.2 observer
339  constexpr rep
340  count() const
341  { return __r; }
342 
343  // 20.11.5.3 arithmetic
344  constexpr duration
345  operator+() const
346  { return *this; }
347 
348  constexpr duration
349  operator-() const
350  { return duration(-__r); }
351 
352  duration&
353  operator++()
354  {
355  ++__r;
356  return *this;
357  }
358 
359  duration
360  operator++(int)
361  { return duration(__r++); }
362 
363  duration&
364  operator--()
365  {
366  --__r;
367  return *this;
368  }
369 
370  duration
371  operator--(int)
372  { return duration(__r--); }
373 
374  duration&
375  operator+=(const duration& __d)
376  {
377  __r += __d.count();
378  return *this;
379  }
380 
381  duration&
382  operator-=(const duration& __d)
383  {
384  __r -= __d.count();
385  return *this;
386  }
387 
388  duration&
389  operator*=(const rep& __rhs)
390  {
391  __r *= __rhs;
392  return *this;
393  }
394 
395  duration&
396  operator/=(const rep& __rhs)
397  {
398  __r /= __rhs;
399  return *this;
400  }
401 
402  // DR 934.
403  template<typename _Rep2 = rep>
404  typename enable_if<!treat_as_floating_point<_Rep2>::value,
405  duration&>::type
406  operator%=(const rep& __rhs)
407  {
408  __r %= __rhs;
409  return *this;
410  }
411 
412  template<typename _Rep2 = rep>
413  typename enable_if<!treat_as_floating_point<_Rep2>::value,
414  duration&>::type
415  operator%=(const duration& __d)
416  {
417  __r %= __d.count();
418  return *this;
419  }
420 
421  // 20.11.5.4 special values
422  static constexpr duration
423  zero()
424  { return duration(duration_values<rep>::zero()); }
425 
426  static constexpr duration
427  min()
428  { return duration(duration_values<rep>::min()); }
429 
430  static constexpr duration
431  max()
432  { return duration(duration_values<rep>::max()); }
433 
434  private:
435  rep __r;
436  };
437 
438  template<typename _Rep1, typename _Period1,
439  typename _Rep2, typename _Period2>
440  constexpr typename common_type<duration<_Rep1, _Period1>,
441  duration<_Rep2, _Period2>>::type
442  operator+(const duration<_Rep1, _Period1>& __lhs,
443  const duration<_Rep2, _Period2>& __rhs)
444  {
445  typedef duration<_Rep1, _Period1> __dur1;
446  typedef duration<_Rep2, _Period2> __dur2;
447  typedef typename common_type<__dur1,__dur2>::type __cd;
448  return __cd(__cd(__lhs).count() + __cd(__rhs).count());
449  }
450 
451  template<typename _Rep1, typename _Period1,
452  typename _Rep2, typename _Period2>
453  constexpr typename common_type<duration<_Rep1, _Period1>,
454  duration<_Rep2, _Period2>>::type
455  operator-(const duration<_Rep1, _Period1>& __lhs,
456  const duration<_Rep2, _Period2>& __rhs)
457  {
458  typedef duration<_Rep1, _Period1> __dur1;
459  typedef duration<_Rep2, _Period2> __dur2;
460  typedef typename common_type<__dur1,__dur2>::type __cd;
461  return __cd(__cd(__lhs).count() - __cd(__rhs).count());
462  }
463 
464  template<typename _Rep1, typename _Rep2, bool =
465  is_convertible<_Rep2,
466  typename common_type<_Rep1, _Rep2>::type>::value>
467  struct __common_rep_type { };
468 
469  template<typename _Rep1, typename _Rep2>
470  struct __common_rep_type<_Rep1, _Rep2, true>
471  { typedef typename common_type<_Rep1, _Rep2>::type type; };
472 
473  template<typename _Rep1, typename _Period, typename _Rep2>
474  constexpr
475  duration<typename __common_rep_type<_Rep1, _Rep2>::type, _Period>
476  operator*(const duration<_Rep1, _Period>& __d, const _Rep2& __s)
477  {
478  typedef duration<typename common_type<_Rep1, _Rep2>::type, _Period>
479  __cd;
480  return __cd(__cd(__d).count() * __s);
481  }
482 
483  template<typename _Rep1, typename _Rep2, typename _Period>
484  constexpr
485  duration<typename __common_rep_type<_Rep2, _Rep1>::type, _Period>
486  operator*(const _Rep1& __s, const duration<_Rep2, _Period>& __d)
487  { return __d * __s; }
488 
489  template<typename _Rep1, typename _Period, typename _Rep2>
490  constexpr duration<typename __common_rep_type<_Rep1, typename
491  enable_if<!__is_duration<_Rep2>::value, _Rep2>::type>::type, _Period>
492  operator/(const duration<_Rep1, _Period>& __d, const _Rep2& __s)
493  {
494  typedef duration<typename common_type<_Rep1, _Rep2>::type, _Period>
495  __cd;
496  return __cd(__cd(__d).count() / __s);
497  }
498 
499  template<typename _Rep1, typename _Period1,
500  typename _Rep2, typename _Period2>
501  constexpr typename common_type<_Rep1, _Rep2>::type
502  operator/(const duration<_Rep1, _Period1>& __lhs,
503  const duration<_Rep2, _Period2>& __rhs)
504  {
505  typedef duration<_Rep1, _Period1> __dur1;
506  typedef duration<_Rep2, _Period2> __dur2;
507  typedef typename common_type<__dur1,__dur2>::type __cd;
508  return __cd(__lhs).count() / __cd(__rhs).count();
509  }
510 
511  // DR 934.
512  template<typename _Rep1, typename _Period, typename _Rep2>
513  constexpr duration<typename __common_rep_type<_Rep1, typename
514  enable_if<!__is_duration<_Rep2>::value, _Rep2>::type>::type, _Period>
515  operator%(const duration<_Rep1, _Period>& __d, const _Rep2& __s)
516  {
517  typedef duration<typename common_type<_Rep1, _Rep2>::type, _Period>
518  __cd;
519  return __cd(__cd(__d).count() % __s);
520  }
521 
522  template<typename _Rep1, typename _Period1,
523  typename _Rep2, typename _Period2>
524  constexpr typename common_type<duration<_Rep1, _Period1>,
525  duration<_Rep2, _Period2>>::type
526  operator%(const duration<_Rep1, _Period1>& __lhs,
527  const duration<_Rep2, _Period2>& __rhs)
528  {
529  typedef duration<_Rep1, _Period1> __dur1;
530  typedef duration<_Rep2, _Period2> __dur2;
531  typedef typename common_type<__dur1,__dur2>::type __cd;
532  return __cd(__cd(__lhs).count() % __cd(__rhs).count());
533  }
534 
535  // comparisons
536  template<typename _Rep1, typename _Period1,
537  typename _Rep2, typename _Period2>
538  constexpr bool
539  operator==(const duration<_Rep1, _Period1>& __lhs,
540  const duration<_Rep2, _Period2>& __rhs)
541  {
542  typedef duration<_Rep1, _Period1> __dur1;
543  typedef duration<_Rep2, _Period2> __dur2;
544  typedef typename common_type<__dur1,__dur2>::type __ct;
545  return __ct(__lhs).count() == __ct(__rhs).count();
546  }
547 
548  template<typename _Rep1, typename _Period1,
549  typename _Rep2, typename _Period2>
550  constexpr bool
551  operator<(const duration<_Rep1, _Period1>& __lhs,
552  const duration<_Rep2, _Period2>& __rhs)
553  {
554  typedef duration<_Rep1, _Period1> __dur1;
555  typedef duration<_Rep2, _Period2> __dur2;
556  typedef typename common_type<__dur1,__dur2>::type __ct;
557  return __ct(__lhs).count() < __ct(__rhs).count();
558  }
559 
560  template<typename _Rep1, typename _Period1,
561  typename _Rep2, typename _Period2>
562  constexpr bool
563  operator!=(const duration<_Rep1, _Period1>& __lhs,
564  const duration<_Rep2, _Period2>& __rhs)
565  { return !(__lhs == __rhs); }
566 
567  template<typename _Rep1, typename _Period1,
568  typename _Rep2, typename _Period2>
569  constexpr bool
570  operator<=(const duration<_Rep1, _Period1>& __lhs,
571  const duration<_Rep2, _Period2>& __rhs)
572  { return !(__rhs < __lhs); }
573 
574  template<typename _Rep1, typename _Period1,
575  typename _Rep2, typename _Period2>
576  constexpr bool
577  operator>(const duration<_Rep1, _Period1>& __lhs,
578  const duration<_Rep2, _Period2>& __rhs)
579  { return __rhs < __lhs; }
580 
581  template<typename _Rep1, typename _Period1,
582  typename _Rep2, typename _Period2>
583  constexpr bool
584  operator>=(const duration<_Rep1, _Period1>& __lhs,
585  const duration<_Rep2, _Period2>& __rhs)
586  { return !(__lhs < __rhs); }
587 
588  /// nanoseconds
589  typedef duration<int64_t, nano> nanoseconds;
590 
591  /// microseconds
592  typedef duration<int64_t, micro> microseconds;
593 
594  /// milliseconds
595  typedef duration<int64_t, milli> milliseconds;
596 
597  /// seconds
598  typedef duration<int64_t> seconds;
599 
600  /// minutes
601  typedef duration<int64_t, ratio< 60>> minutes;
602 
603  /// hours
604  typedef duration<int64_t, ratio<3600>> hours;
605 
606  /// time_point
607  template<typename _Clock, typename _Dur>
608  struct time_point
609  {
610  typedef _Clock clock;
611  typedef _Dur duration;
612  typedef typename duration::rep rep;
613  typedef typename duration::period period;
614 
615  constexpr time_point() : __d(duration::zero())
616  { }
617 
618  constexpr explicit time_point(const duration& __dur)
619  : __d(__dur)
620  { }
621 
622  // conversions
623  template<typename _Dur2>
624  constexpr time_point(const time_point<clock, _Dur2>& __t)
625  : __d(__t.time_since_epoch())
626  { }
627 
628  // observer
629  constexpr duration
630  time_since_epoch() const
631  { return __d; }
632 
633  // arithmetic
634  time_point&
635  operator+=(const duration& __dur)
636  {
637  __d += __dur;
638  return *this;
639  }
640 
641  time_point&
642  operator-=(const duration& __dur)
643  {
644  __d -= __dur;
645  return *this;
646  }
647 
648  // special values
649  static constexpr time_point
650  min()
651  { return time_point(duration::min()); }
652 
653  static constexpr time_point
654  max()
655  { return time_point(duration::max()); }
656 
657  private:
658  duration __d;
659  };
660 
661  /// time_point_cast
662  template<typename _ToDur, typename _Clock, typename _Dur>
663  constexpr typename enable_if<__is_duration<_ToDur>::value,
664  time_point<_Clock, _ToDur>>::type
665  time_point_cast(const time_point<_Clock, _Dur>& __t)
666  {
667  typedef time_point<_Clock, _ToDur> __time_point;
668  return __time_point(duration_cast<_ToDur>(__t.time_since_epoch()));
669  }
670 
671 #if __cplusplus > 201402L
672  template<typename _ToDur, typename _Clock, typename _Dur>
673  constexpr
674  enable_if_t<__is_duration<_ToDur>::value, time_point<_Clock, _ToDur>>
675  floor(const time_point<_Clock, _Dur>& __tp)
676  {
677  return time_point<_Clock, _ToDur>{
678  chrono::floor<_ToDur>(__tp.time_since_epoch())};
679  }
680 
681  template<typename _ToDur, typename _Clock, typename _Dur>
682  constexpr
683  enable_if_t<__is_duration<_ToDur>::value, time_point<_Clock, _ToDur>>
684  ceil(const time_point<_Clock, _Dur>& __tp)
685  {
686  return time_point<_Clock, _ToDur>{
687  chrono::ceil<_ToDur>(__tp.time_since_epoch())};
688  }
689 
690  template<typename _ToDur, typename _Clock, typename _Dur>
691  constexpr enable_if_t<
692  __and_<__is_duration<_ToDur>,
693  __not_<treat_as_floating_point<typename _ToDur::rep>>>::value,
694  time_point<_Clock, _ToDur>>
695  round(const time_point<_Clock, _Dur>& __tp)
696  {
697  return time_point<_Clock, _ToDur>{
698  chrono::round<_ToDur>(__tp.time_since_epoch())};
699  }
700 #endif // C++17
701 
702  template<typename _Clock, typename _Dur1,
703  typename _Rep2, typename _Period2>
704  constexpr time_point<_Clock,
705  typename common_type<_Dur1, duration<_Rep2, _Period2>>::type>
706  operator+(const time_point<_Clock, _Dur1>& __lhs,
707  const duration<_Rep2, _Period2>& __rhs)
708  {
709  typedef duration<_Rep2, _Period2> __dur2;
710  typedef typename common_type<_Dur1,__dur2>::type __ct;
711  typedef time_point<_Clock, __ct> __time_point;
712  return __time_point(__lhs.time_since_epoch() + __rhs);
713  }
714 
715  template<typename _Rep1, typename _Period1,
716  typename _Clock, typename _Dur2>
717  constexpr time_point<_Clock,
718  typename common_type<duration<_Rep1, _Period1>, _Dur2>::type>
719  operator+(const duration<_Rep1, _Period1>& __lhs,
720  const time_point<_Clock, _Dur2>& __rhs)
721  {
722  typedef duration<_Rep1, _Period1> __dur1;
723  typedef typename common_type<__dur1,_Dur2>::type __ct;
724  typedef time_point<_Clock, __ct> __time_point;
725  return __time_point(__rhs.time_since_epoch() + __lhs);
726  }
727 
728  template<typename _Clock, typename _Dur1,
729  typename _Rep2, typename _Period2>
730  constexpr time_point<_Clock,
731  typename common_type<_Dur1, duration<_Rep2, _Period2>>::type>
732  operator-(const time_point<_Clock, _Dur1>& __lhs,
733  const duration<_Rep2, _Period2>& __rhs)
734  {
735  typedef duration<_Rep2, _Period2> __dur2;
736  typedef typename common_type<_Dur1,__dur2>::type __ct;
737  typedef time_point<_Clock, __ct> __time_point;
738  return __time_point(__lhs.time_since_epoch() -__rhs);
739  }
740 
741  template<typename _Clock, typename _Dur1, typename _Dur2>
742  constexpr typename common_type<_Dur1, _Dur2>::type
743  operator-(const time_point<_Clock, _Dur1>& __lhs,
744  const time_point<_Clock, _Dur2>& __rhs)
745  { return __lhs.time_since_epoch() - __rhs.time_since_epoch(); }
746 
747  template<typename _Clock, typename _Dur1, typename _Dur2>
748  constexpr bool
749  operator==(const time_point<_Clock, _Dur1>& __lhs,
750  const time_point<_Clock, _Dur2>& __rhs)
751  { return __lhs.time_since_epoch() == __rhs.time_since_epoch(); }
752 
753  template<typename _Clock, typename _Dur1, typename _Dur2>
754  constexpr bool
755  operator!=(const time_point<_Clock, _Dur1>& __lhs,
756  const time_point<_Clock, _Dur2>& __rhs)
757  { return !(__lhs == __rhs); }
758 
759  template<typename _Clock, typename _Dur1, typename _Dur2>
760  constexpr bool
761  operator<(const time_point<_Clock, _Dur1>& __lhs,
762  const time_point<_Clock, _Dur2>& __rhs)
763  { return __lhs.time_since_epoch() < __rhs.time_since_epoch(); }
764 
765  template<typename _Clock, typename _Dur1, typename _Dur2>
766  constexpr bool
767  operator<=(const time_point<_Clock, _Dur1>& __lhs,
768  const time_point<_Clock, _Dur2>& __rhs)
769  { return !(__rhs < __lhs); }
770 
771  template<typename _Clock, typename _Dur1, typename _Dur2>
772  constexpr bool
773  operator>(const time_point<_Clock, _Dur1>& __lhs,
774  const time_point<_Clock, _Dur2>& __rhs)
775  { return __rhs < __lhs; }
776 
777  template<typename _Clock, typename _Dur1, typename _Dur2>
778  constexpr bool
779  operator>=(const time_point<_Clock, _Dur1>& __lhs,
780  const time_point<_Clock, _Dur2>& __rhs)
781  { return !(__lhs < __rhs); }
782 
783 
784  // Clocks.
785 
786  // Why nanosecond resolution as the default?
787  // Why have std::system_clock always count in the highest
788  // resolution (ie nanoseconds), even if on some OSes the low 3
789  // or 9 decimal digits will be always zero? This allows later
790  // implementations to change the system_clock::now()
791  // implementation any time to provide better resolution without
792  // changing function signature or units.
793 
794  // To support the (forward) evolution of the library's defined
795  // clocks, wrap inside inline namespace so that the current
796  // defintions of system_clock, steady_clock, and
797  // high_resolution_clock types are uniquely mangled. This way, new
798  // code can use the latests clocks, while the library can contain
799  // compatibility definitions for previous versions. At some
800  // point, when these clocks settle down, the inlined namespaces
801  // can be removed. XXX GLIBCXX_ABI Deprecated
802  inline namespace _V2 {
803 
804  /**
805  * @brief System clock.
806  *
807  * Time returned represents wall time from the system-wide clock.
808  */
809  struct system_clock
810  {
811  typedef chrono::nanoseconds duration;
812  typedef duration::rep rep;
813  typedef duration::period period;
814  typedef chrono::time_point<system_clock, duration> time_point;
815 
816  static_assert(system_clock::duration::min()
817  < system_clock::duration::zero(),
818  "a clock's minimum duration cannot be less than its epoch");
819 
820  static constexpr bool is_steady = false;
821 
822  static time_point
823  now() noexcept;
824 
825  // Map to C API
826  static std::time_t
827  to_time_t(const time_point& __t) noexcept
828  {
829  return std::time_t(duration_cast<chrono::seconds>
830  (__t.time_since_epoch()).count());
831  }
832 
833  static time_point
834  from_time_t(std::time_t __t) noexcept
835  {
836  typedef chrono::time_point<system_clock, seconds> __from;
837  return time_point_cast<system_clock::duration>
838  (__from(chrono::seconds(__t)));
839  }
840  };
841 
842 
843  /**
844  * @brief Monotonic clock
845  *
846  * Time returned has the property of only increasing at a uniform rate.
847  */
848  struct steady_clock
849  {
850  typedef chrono::nanoseconds duration;
851  typedef duration::rep rep;
852  typedef duration::period period;
853  typedef chrono::time_point<steady_clock, duration> time_point;
854 
855  static constexpr bool is_steady = true;
856 
857  static time_point
858  now() noexcept;
859  };
860 
861 
862  /**
863  * @brief Highest-resolution clock
864  *
865  * This is the clock "with the shortest tick period." Alias to
866  * std::system_clock until higher-than-nanosecond definitions
867  * become feasible.
868  */
869  using high_resolution_clock = system_clock;
870 
871  } // end inline namespace _V2
872 
873  _GLIBCXX_END_NAMESPACE_VERSION
874  } // namespace chrono
875 
876 #if __cplusplus > 201103L
877 
878 #define __cpp_lib_chrono_udls 201304
879 
880  inline namespace literals
881  {
882  inline namespace chrono_literals
883  {
884  _GLIBCXX_BEGIN_NAMESPACE_VERSION
885 
886  template<typename _Rep, unsigned long long _Val>
887  struct _Checked_integral_constant
888  : integral_constant<_Rep, static_cast<_Rep>(_Val)>
889  {
890  static_assert(_Checked_integral_constant::value >= 0
891  && _Checked_integral_constant::value == _Val,
892  "literal value cannot be represented by duration type");
893  };
894 
895  template<typename _Dur, char... _Digits>
896  constexpr _Dur __check_overflow()
897  {
898  using _Val = __parse_int::_Parse_int<_Digits...>;
899  using _Rep = typename _Dur::rep;
900  // TODO: should be simply integral_constant<_Rep, _Val::value>
901  // but GCC doesn't reject narrowing conversions to _Rep.
902  using _CheckedVal = _Checked_integral_constant<_Rep, _Val::value>;
903  return _Dur{_CheckedVal::value};
904  }
905 
906  constexpr chrono::duration<long double, ratio<3600,1>>
907  operator""h(long double __hours)
908  { return chrono::duration<long double, ratio<3600,1>>{__hours}; }
909 
910  template <char... _Digits>
911  constexpr chrono::hours
912  operator""h()
913  { return __check_overflow<chrono::hours, _Digits...>(); }
914 
915  constexpr chrono::duration<long double, ratio<60,1>>
916  operator""min(long double __mins)
917  { return chrono::duration<long double, ratio<60,1>>{__mins}; }
918 
919  template <char... _Digits>
920  constexpr chrono::minutes
921  operator""min()
922  { return __check_overflow<chrono::minutes, _Digits...>(); }
923 
924  constexpr chrono::duration<long double>
925  operator""s(long double __secs)
926  { return chrono::duration<long double>{__secs}; }
927 
928  template <char... _Digits>
929  constexpr chrono::seconds
930  operator""s()
931  { return __check_overflow<chrono::seconds, _Digits...>(); }
932 
933  constexpr chrono::duration<long double, milli>
934  operator""ms(long double __msecs)
935  { return chrono::duration<long double, milli>{__msecs}; }
936 
937  template <char... _Digits>
938  constexpr chrono::milliseconds
939  operator""ms()
940  { return __check_overflow<chrono::milliseconds, _Digits...>(); }
941 
942  constexpr chrono::duration<long double, micro>
943  operator""us(long double __usecs)
944  { return chrono::duration<long double, micro>{__usecs}; }
945 
946  template <char... _Digits>
947  constexpr chrono::microseconds
948  operator""us()
949  { return __check_overflow<chrono::microseconds, _Digits...>(); }
950 
951  constexpr chrono::duration<long double, nano>
952  operator""ns(long double __nsecs)
953  { return chrono::duration<long double, nano>{__nsecs}; }
954 
955  template <char... _Digits>
956  constexpr chrono::nanoseconds
957  operator""ns()
958  { return __check_overflow<chrono::nanoseconds, _Digits...>(); }
959 
960  _GLIBCXX_END_NAMESPACE_VERSION
961  } // inline namespace chrono_literals
962  } // inline namespace literals
963 
964  namespace chrono
965  {
966  _GLIBCXX_BEGIN_NAMESPACE_VERSION
967 
968  using namespace literals::chrono_literals;
969 
970  _GLIBCXX_END_NAMESPACE_VERSION
971  } // namespace chrono
972 
973 #endif // __cplusplus > 201103L
974 
975  // @} group chrono
976 } // namespace std
977 
978 #endif //_GLIBCXX_USE_C99_STDINT_TR1
979 
980 #endif // C++11
981 
982 #endif //_GLIBCXX_CHRONO