1 //  duration.hpp  --------------------------------------------------------------//
2 
3 //  Copyright 2008 Howard Hinnant
4 //  Copyright 2008 Beman Dawes
5 //  Copyright 2009-2011 Vicente J. Botet Escriba
6 
7 //  Distributed under the Boost Software License, Version 1.0.
8 //  See http://www.boost.org/LICENSE_1_0.txt
9 
10 /*
11 
12 This code was derived by Beman Dawes from Howard Hinnant's time2_demo prototype.
13 Many thanks to Howard for making his code available under the Boost license.
14 The original code was modified to conform to Boost conventions and to section
15 20.9 Time utilities [time] of the C++ committee's working paper N2798.
16 See http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2798.pdf.
17 
18 time2_demo contained this comment:
19 
20     Much thanks to Andrei Alexandrescu,
21                    Walter Brown,
22                    Peter Dimov,
23                    Jeff Garland,
24                    Terry Golubiewski,
25                    Daniel Krugler,
26                    Anthony Williams.
27 */
28 
29 
30 #ifndef BOOST_CHRONO_DURATION_HPP
31 #define BOOST_CHRONO_DURATION_HPP
32 
33 #include <boost/chrono/config.hpp>
34 #include <boost/chrono/detail/static_assert.hpp>
35 
36 #include <climits>
37 #include <limits>
38 
39 
40 #include <boost/mpl/logical.hpp>
41 #include <boost/ratio/ratio.hpp>
42 #include <boost/type_traits/common_type.hpp>
43 #include <boost/type_traits/is_arithmetic.hpp>
44 #include <boost/type_traits/is_convertible.hpp>
45 #include <boost/type_traits/is_floating_point.hpp>
46 #include <boost/type_traits/is_unsigned.hpp>
47 #include <boost/chrono/detail/is_evenly_divisible_by.hpp>
48 
49 #include <boost/cstdint.hpp>
50 #include <boost/utility/enable_if.hpp>
51 #include <boost/detail/workaround.hpp>
52 #include <boost/integer_traits.hpp>
53 
54 #if !defined(BOOST_NO_CXX11_STATIC_ASSERT) || !defined(BOOST_CHRONO_USES_MPL_ASSERT)
55 #define BOOST_CHRONO_A_DURATION_REPRESENTATION_CAN_NOT_BE_A_DURATION        "A duration representation can not be a duration"
56 #define BOOST_CHRONO_SECOND_TEMPLATE_PARAMETER_OF_DURATION_MUST_BE_A_STD_RATIO "Second template parameter of duration must be a boost::ratio"
57 #define BOOST_CHRONO_DURATION_PERIOD_MUST_BE_POSITIVE "duration period must be positive"
58 #define BOOST_CHRONO_SECOND_TEMPLATE_PARAMETER_OF_TIME_POINT_MUST_BE_A_BOOST_CHRONO_DURATION "Second template parameter of time_point must be a boost::chrono::duration"
59 #endif
60 
61 #ifndef BOOST_CHRONO_HEADER_ONLY
62 // this must occur after all of the includes and before any code appears:
63 #include <boost/config/abi_prefix.hpp> // must be the last #include
64 #endif
65 
66 //----------------------------------------------------------------------------//
67 //                                                                            //
68 //                        20.9 Time utilities [time]                          //
69 //                                 synopsis                                   //
70 //                                                                            //
71 //----------------------------------------------------------------------------//
72 
73 namespace boost {
74 namespace chrono {
75 
76     template <class Rep, class Period = ratio<1> >
77     class duration;
78 
79     namespace detail
80     {
81     template <class T>
82       struct is_duration
83         : boost::false_type {};
84 
85     template <class Rep, class Period>
86       struct is_duration<duration<Rep, Period> >
87         : boost::true_type  {};
88 
89     template <class Duration, class Rep, bool = is_duration<Rep>::value>
90     struct duration_divide_result
91     {
92     };
93 
94     template <class Duration, class Rep2,
95         bool = (
96                     ((boost::is_convertible<typename Duration::rep,
97                         typename common_type<typename Duration::rep, Rep2>::type>::value))
98                 &&  ((boost::is_convertible<Rep2,
99                         typename common_type<typename Duration::rep, Rep2>::type>::value))
100                 )
101         >
102     struct duration_divide_imp
103     {
104     };
105 
106     template <class Rep1, class Period, class Rep2>
107     struct duration_divide_imp<duration<Rep1, Period>, Rep2, true>
108     {
109         typedef duration<typename common_type<Rep1, Rep2>::type, Period> type;
110     };
111 
112     template <class Rep1, class Period, class Rep2>
113     struct duration_divide_result<duration<Rep1, Period>, Rep2, false>
114         : duration_divide_imp<duration<Rep1, Period>, Rep2>
115     {
116     };
117 
118 ///
119     template <class Rep, class Duration, bool = is_duration<Rep>::value>
120     struct duration_divide_result2
121     {
122     };
123 
124     template <class Rep, class Duration,
125         bool = (
126                     ((boost::is_convertible<typename Duration::rep,
127                         typename common_type<typename Duration::rep, Rep>::type>::value))
128                 &&  ((boost::is_convertible<Rep,
129                         typename common_type<typename Duration::rep, Rep>::type>::value))
130                 )
131         >
132     struct duration_divide_imp2
133     {
134     };
135 
136     template <class Rep1, class Rep2, class Period >
137     struct duration_divide_imp2<Rep1, duration<Rep2, Period>, true>
138     {
139         //typedef typename common_type<Rep1, Rep2>::type type;
140         typedef double type;
141     };
142 
143     template <class Rep1, class Rep2, class Period >
144     struct duration_divide_result2<Rep1, duration<Rep2, Period>, false>
145         : duration_divide_imp2<Rep1, duration<Rep2, Period> >
146     {
147     };
148 
149 ///
150     template <class Duration, class Rep, bool = is_duration<Rep>::value>
151     struct duration_modulo_result
152     {
153     };
154 
155     template <class Duration, class Rep2,
156         bool = (
157                     //boost::is_convertible<typename Duration::rep,
158                         //typename common_type<typename Duration::rep, Rep2>::type>::value
159                 //&&
160     boost::is_convertible<Rep2,
161                         typename common_type<typename Duration::rep, Rep2>::type>::value
162                 )
163         >
164     struct duration_modulo_imp
165     {
166     };
167 
168     template <class Rep1, class Period, class Rep2>
169     struct duration_modulo_imp<duration<Rep1, Period>, Rep2, true>
170     {
171         typedef duration<typename common_type<Rep1, Rep2>::type, Period> type;
172     };
173 
174     template <class Rep1, class Period, class Rep2>
175     struct duration_modulo_result<duration<Rep1, Period>, Rep2, false>
176         : duration_modulo_imp<duration<Rep1, Period>, Rep2>
177     {
178     };
179 
180 } // namespace detail
181 } // namespace chrono
182 
183 
184 // common_type trait specializations
185 
186 template <class Rep1, class Period1, class Rep2, class Period2>
187 struct common_type<chrono::duration<Rep1, Period1>,
188                      chrono::duration<Rep2, Period2> >;
189 
190 
191 namespace chrono {
192 
193     // customization traits
194     template <class Rep> struct treat_as_floating_point;
195     template <class Rep> struct duration_values;
196 
197     // convenience typedefs
198     typedef duration<boost::int_least64_t, nano> nanoseconds;    // at least 64 bits needed
199     typedef duration<boost::int_least64_t, micro> microseconds;  // at least 55 bits needed
200     typedef duration<boost::int_least64_t, milli> milliseconds;  // at least 45 bits needed
201     typedef duration<boost::int_least64_t> seconds;              // at least 35 bits needed
202     typedef duration<boost::int_least32_t, ratio< 60> > minutes; // at least 29 bits needed
203     typedef duration<boost::int_least32_t, ratio<3600> > hours;  // at least 23 bits needed
204 
205 //----------------------------------------------------------------------------//
206 //                          duration helpers                                  //
207 //----------------------------------------------------------------------------//
208 
209 namespace detail
210 {
211 
212     // duration_cast
213 
214     // duration_cast is the heart of this whole prototype.  It can convert any
215     //   duration to any other.  It is also (implicitly) used in converting
216     //   time_points.  The conversion is always exact if possible.  And it is
217     //   always as efficient as hand written code.  If different representations
218     //   are involved, care is taken to never require implicit conversions.
219     //   Instead static_cast is used explicitly for every required conversion.
220     //   If there are a mixture of integral and floating point representations,
221     //   the use of common_type ensures that the most logical "intermediate"
222     //   representation is used.
223     template <class FromDuration, class ToDuration,
224               class Period,
225               bool PeriodNumEq1,
226               bool PeriodDenEq1>
227     struct duration_cast_aux;
228 
229     // When the two periods are the same, all that is left to do is static_cast from
230     //   the source representation to the target representation (which may be a no-op).
231     //   This conversion is always exact as long as the static_cast from the source
232     //   representation to the destination representation is exact.
233     template <class FromDuration, class ToDuration, class Period>
234     struct duration_cast_aux<FromDuration, ToDuration, Period, true, true>
235     {
operator ()boost::chrono::detail::duration_cast_aux236         BOOST_CONSTEXPR ToDuration operator()(const FromDuration& fd) const
237         {
238             return ToDuration(static_cast<typename ToDuration::rep>(fd.count()));
239         }
240     };
241 
242     // When the numerator of FromPeriod / ToPeriod is 1, then all we need to do is
243     //   divide by the denominator of FromPeriod / ToPeriod.  The common_type of
244     //   the two representations is used for the intermediate computation before
245     //   static_cast'ing to the destination.
246     //   This conversion is generally not exact because of the division (but could be
247     //   if you get lucky on the run time value of fd.count()).
248     template <class FromDuration, class ToDuration, class Period>
249     struct duration_cast_aux<FromDuration, ToDuration, Period, true, false>
250     {
operator ()boost::chrono::detail::duration_cast_aux251         BOOST_CONSTEXPR ToDuration operator()(const FromDuration& fd) const
252         {
253             typedef typename common_type<
254                 typename ToDuration::rep,
255                 typename FromDuration::rep,
256                 boost::intmax_t>::type C;
257             return ToDuration(static_cast<typename ToDuration::rep>(
258                               static_cast<C>(fd.count()) / static_cast<C>(Period::den)));
259         }
260     };
261 
262     // When the denominator of FromPeriod / ToPeriod is 1, then all we need to do is
263     //   multiply by the numerator of FromPeriod / ToPeriod.  The common_type of
264     //   the two representations is used for the intermediate computation before
265     //   static_cast'ing to the destination.
266     //   This conversion is always exact as long as the static_cast's involved are exact.
267     template <class FromDuration, class ToDuration, class Period>
268     struct duration_cast_aux<FromDuration, ToDuration, Period, false, true>
269     {
operator ()boost::chrono::detail::duration_cast_aux270         BOOST_CONSTEXPR ToDuration operator()(const FromDuration& fd) const
271         {
272             typedef typename common_type<
273               typename ToDuration::rep,
274               typename FromDuration::rep,
275               boost::intmax_t>::type C;
276             return ToDuration(static_cast<typename ToDuration::rep>(
277                               static_cast<C>(fd.count()) * static_cast<C>(Period::num)));
278         }
279     };
280 
281     // When neither the numerator or denominator of FromPeriod / ToPeriod is 1, then we need to
282     //   multiply by the numerator and divide by the denominator of FromPeriod / ToPeriod.  The
283     //   common_type of the two representations is used for the intermediate computation before
284     //   static_cast'ing to the destination.
285     //   This conversion is generally not exact because of the division (but could be
286     //   if you get lucky on the run time value of fd.count()).
287     template <class FromDuration, class ToDuration, class Period>
288     struct duration_cast_aux<FromDuration, ToDuration, Period, false, false>
289     {
operator ()boost::chrono::detail::duration_cast_aux290         BOOST_CONSTEXPR ToDuration operator()(const FromDuration& fd) const
291         {
292             typedef typename common_type<
293               typename ToDuration::rep,
294               typename FromDuration::rep,
295               boost::intmax_t>::type C;
296             return ToDuration(static_cast<typename ToDuration::rep>(
297                static_cast<C>(fd.count()) * static_cast<C>(Period::num)
298                  / static_cast<C>(Period::den)));
299         }
300     };
301 
302     template <class FromDuration, class ToDuration>
303     struct duration_cast {
304         typedef typename ratio_divide<typename FromDuration::period,
305               typename ToDuration::period>::type Period;
306         typedef duration_cast_aux<
307             FromDuration,
308             ToDuration,
309             Period,
310             Period::num == 1,
311             Period::den == 1
312         > Aux;
operator ()boost::chrono::detail::duration_cast313         BOOST_CONSTEXPR ToDuration operator()(const FromDuration& fd) const
314         {
315             return Aux()(fd);
316         }
317     };
318 
319 } // namespace detail
320 
321 //----------------------------------------------------------------------------//
322 //                                                                            //
323 //      20.9.2 Time-related traits [time.traits]                              //
324 //                                                                            //
325 //----------------------------------------------------------------------------//
326 //----------------------------------------------------------------------------//
327 //      20.9.2.1 treat_as_floating_point [time.traits.is_fp]                        //
328 //      Probably should have been treat_as_floating_point. Editor notifed.    //
329 //----------------------------------------------------------------------------//
330 
331     // Support bidirectional (non-exact) conversions for floating point rep types
332     //   (or user defined rep types which specialize treat_as_floating_point).
333     template <class Rep>
334     struct treat_as_floating_point : boost::is_floating_point<Rep> {};
335 
336 //----------------------------------------------------------------------------//
337 //      20.9.2.2 duration_values [time.traits.duration_values]                //
338 //----------------------------------------------------------------------------//
339 
340 namespace detail {
341     template <class T, bool = is_arithmetic<T>::value>
342     struct chrono_numeric_limits {
lowestboost::chrono::detail::chrono_numeric_limits343         static BOOST_CHRONO_LIB_CONSTEXPR T lowest() BOOST_CHRONO_LIB_NOEXCEPT_OR_THROW {return (std::numeric_limits<T>::min)  ();}
344     };
345 
346     template <class T>
347     struct chrono_numeric_limits<T,true> {
lowestboost::chrono::detail::chrono_numeric_limits348         static BOOST_CHRONO_LIB_CONSTEXPR T lowest() BOOST_CHRONO_LIB_NOEXCEPT_OR_THROW {return (std::numeric_limits<T>::min)  ();}
349     };
350 
351     template <>
352     struct chrono_numeric_limits<float,true> {
lowestboost::chrono::detail::chrono_numeric_limits353         static BOOST_CHRONO_LIB_CONSTEXPR float lowest() BOOST_CHRONO_LIB_NOEXCEPT_OR_THROW
354         {
355             return -(std::numeric_limits<float>::max) ();
356         }
357     };
358 
359     template <>
360     struct chrono_numeric_limits<double,true> {
lowestboost::chrono::detail::chrono_numeric_limits361         static BOOST_CHRONO_LIB_CONSTEXPR double lowest() BOOST_CHRONO_LIB_NOEXCEPT_OR_THROW
362         {
363             return -(std::numeric_limits<double>::max) ();
364         }
365     };
366 
367     template <>
368     struct chrono_numeric_limits<long double,true> {
lowestboost::chrono::detail::chrono_numeric_limits369         static BOOST_CHRONO_LIB_CONSTEXPR long double lowest() BOOST_CHRONO_LIB_NOEXCEPT_OR_THROW
370         {
371             return -(std::numeric_limits<long double>::max)();
372         }
373     };
374 
375     template <class T>
376     struct numeric_limits : chrono_numeric_limits<typename remove_cv<T>::type>
377     {};
378 
379 }
380 template <class Rep>
381 struct duration_values
382 {
zeroboost::chrono::duration_values383     static BOOST_CONSTEXPR Rep zero() {return Rep(0);}
BOOST_PREVENT_MACRO_SUBSTITUTIONboost::chrono::duration_values384     static BOOST_CHRONO_LIB_CONSTEXPR Rep max BOOST_PREVENT_MACRO_SUBSTITUTION ()
385     {
386         return (std::numeric_limits<Rep>::max)();
387     }
388 
BOOST_PREVENT_MACRO_SUBSTITUTIONboost::chrono::duration_values389     static BOOST_CHRONO_LIB_CONSTEXPR Rep min BOOST_PREVENT_MACRO_SUBSTITUTION ()
390     {
391         return detail::numeric_limits<Rep>::lowest();
392     }
393 };
394 
395 }  // namespace chrono
396 
397 //----------------------------------------------------------------------------//
398 //      20.9.2.3 Specializations of common_type [time.traits.specializations] //
399 //----------------------------------------------------------------------------//
400 
401 template <class Rep1, class Period1, class Rep2, class Period2>
402 struct common_type<chrono::duration<Rep1, Period1>,
403                    chrono::duration<Rep2, Period2> >
404 {
405   typedef chrono::duration<typename common_type<Rep1, Rep2>::type,
406                       typename boost::ratio_gcd<Period1, Period2>::type> type;
407 };
408 
409 
410 //----------------------------------------------------------------------------//
411 //                                                                            //
412 //         20.9.3 Class template duration [time.duration]                     //
413 //                                                                            //
414 //----------------------------------------------------------------------------//
415 
416 
417 namespace chrono {
418 
419     template <class Rep, class Period>
420     class BOOST_SYMBOL_VISIBLE duration
421     {
422     //BOOST_CHRONO_STATIC_ASSERT(boost::is_integral<Rep>::value, BOOST_CHRONO_A_DURATION_REPRESENTATION_MUST_BE_INTEGRAL, ());
423     BOOST_CHRONO_STATIC_ASSERT(!boost::chrono::detail::is_duration<Rep>::value,
424             BOOST_CHRONO_A_DURATION_REPRESENTATION_CAN_NOT_BE_A_DURATION, ());
425     BOOST_CHRONO_STATIC_ASSERT(boost::ratio_detail::is_ratio<typename Period::type>::value,
426             BOOST_CHRONO_SECOND_TEMPLATE_PARAMETER_OF_DURATION_MUST_BE_A_STD_RATIO, ());
427     BOOST_CHRONO_STATIC_ASSERT(Period::num>0,
428             BOOST_CHRONO_DURATION_PERIOD_MUST_BE_POSITIVE, ());
429     public:
430         typedef Rep rep;
431         typedef Period period;
432     private:
433         rep rep_;
434     public:
435 
436 #if  defined   BOOST_NO_CXX11_DEFAULTED_FUNCTIONS || \
437      defined   BOOST_CHRONO_DURATION_DEFAULTS_TO_ZERO
438         BOOST_FORCEINLINE BOOST_CONSTEXPR
duration()439         duration() : rep_(duration_values<rep>::zero()) { }
440 #else
441         BOOST_CONSTEXPR duration() BOOST_NOEXCEPT : rep_() {};
442 #endif
443         template <class Rep2>
444         BOOST_SYMBOL_VISIBLE BOOST_FORCEINLINE BOOST_CONSTEXPR
duration(const Rep2 & r,typename boost::enable_if<mpl::and_<boost::is_convertible<Rep2,rep>,mpl::or_<treat_as_floating_point<rep>,mpl::and_<mpl::not_<treat_as_floating_point<rep>>,mpl::not_<treat_as_floating_point<Rep2>>>>>>::type * =0)445         explicit duration(const Rep2& r
446         , typename boost::enable_if <
447                     mpl::and_ <
448                         boost::is_convertible<Rep2, rep>,
449                         mpl::or_ <
450                             treat_as_floating_point<rep>,
451                             mpl::and_ <
452                                 mpl::not_ < treat_as_floating_point<rep> >,
453                                 mpl::not_ < treat_as_floating_point<Rep2> >
454                             >
455                         >
456                     >
457                 >::type* = 0
458             ) : rep_(r) { }
459 #if  defined   BOOST_NO_CXX11_DEFAULTED_FUNCTIONS
operator =(const duration & rhs)460         duration& operator=(const duration& rhs)
461         {
462             if (&rhs != this) rep_= rhs.rep_;
463             return *this;
464         }
465 #else
466         duration& operator=(const duration& rhs) = default;
467 #endif
468         // conversions
469         template <class Rep2, class Period2>
470         BOOST_FORCEINLINE BOOST_CONSTEXPR
duration(const duration<Rep2,Period2> & d,typename boost::enable_if<mpl::or_<treat_as_floating_point<rep>,mpl::and_<chrono_detail::is_evenly_divisible_by<Period2,period>,mpl::not_<treat_as_floating_point<Rep2>>>>>::type * =0)471         duration(const duration<Rep2, Period2>& d
472         , typename boost::enable_if <
473                     mpl::or_ <
474                         treat_as_floating_point<rep>,
475                         mpl::and_ <
476                             chrono_detail::is_evenly_divisible_by<Period2, period>,
477                             mpl::not_ < treat_as_floating_point<Rep2> >
478                         >
479                     >
480                 >::type* = 0
481         )
482             : rep_(chrono::detail::duration_cast<duration<Rep2, Period2>, duration>()(d).count()) {}
483 
484         // observer
485 
486         BOOST_CONSTEXPR
count() const487         rep count() const {return rep_;}
488 
489         // arithmetic
490 
491         BOOST_CONSTEXPR
operator +() const492         duration  operator+() const {return duration(rep_);;}
493         BOOST_CONSTEXPR
operator -() const494         duration  operator-() const {return duration(-rep_);}
operator ++()495         duration& operator++()      {++rep_; return *this;}
operator ++(int)496         duration  operator++(int)   {return duration(rep_++);}
operator --()497         duration& operator--()      {--rep_; return *this;}
operator --(int)498         duration  operator--(int)   {return duration(rep_--);}
499 
operator +=(const duration & d)500         duration& operator+=(const duration& d)
501         {
502             rep_ += d.count(); return *this;
503         }
operator -=(const duration & d)504         duration& operator-=(const duration& d)
505         {
506             rep_ -= d.count(); return *this;
507         }
508 
operator *=(const rep & rhs)509         duration& operator*=(const rep& rhs) {rep_ *= rhs; return *this;}
operator /=(const rep & rhs)510         duration& operator/=(const rep& rhs) {rep_ /= rhs; return *this;}
operator %=(const rep & rhs)511         duration& operator%=(const rep& rhs) {rep_ %= rhs; return *this;}
operator %=(const duration & rhs)512         duration& operator%=(const duration& rhs)
513         {
514             rep_ %= rhs.count(); return *this;
515         }
516         // 20.9.3.4 duration special values [time.duration.special]
517 
zero()518         static BOOST_CONSTEXPR duration zero()
519         {
520             return duration(duration_values<rep>::zero());
521         }
BOOST_PREVENT_MACRO_SUBSTITUTION()522         static BOOST_CHRONO_LIB_CONSTEXPR duration min BOOST_PREVENT_MACRO_SUBSTITUTION ()
523         {
524             return duration((duration_values<rep>::min)());
525         }
BOOST_PREVENT_MACRO_SUBSTITUTION()526         static BOOST_CHRONO_LIB_CONSTEXPR duration max BOOST_PREVENT_MACRO_SUBSTITUTION ()
527         {
528             return duration((duration_values<rep>::max)());
529         }
530     };
531 
532 //----------------------------------------------------------------------------//
533 //      20.9.3.5 duration non-member arithmetic [time.duration.nonmember]     //
534 //----------------------------------------------------------------------------//
535 
536     // Duration +
537 
538     template <class Rep1, class Period1, class Rep2, class Period2>
539     inline BOOST_CONSTEXPR
540     typename common_type<duration<Rep1, Period1>, duration<Rep2, Period2> >::type
operator +(const duration<Rep1,Period1> & lhs,const duration<Rep2,Period2> & rhs)541     operator+(const duration<Rep1, Period1>& lhs,
542           const duration<Rep2, Period2>& rhs)
543     {
544       typedef typename common_type<duration<Rep1, Period1>,
545         duration<Rep2, Period2> >::type CD;
546       return CD(CD(lhs).count()+CD(rhs).count());
547     }
548 
549     // Duration -
550 
551     template <class Rep1, class Period1, class Rep2, class Period2>
552     inline BOOST_CONSTEXPR
553     typename common_type<duration<Rep1, Period1>, duration<Rep2, Period2> >::type
operator -(const duration<Rep1,Period1> & lhs,const duration<Rep2,Period2> & rhs)554     operator-(const duration<Rep1, Period1>& lhs,
555           const duration<Rep2, Period2>& rhs)
556     {
557       typedef typename common_type<duration<Rep1, Period1>,
558             duration<Rep2, Period2> >::type CD;
559       return CD(CD(lhs).count()-CD(rhs).count());
560     }
561 
562     // Duration *
563 
564     template <class Rep1, class Period, class Rep2>
565     inline BOOST_CONSTEXPR
566     typename boost::enable_if <
567         mpl::and_ <
568         boost::is_convertible<Rep1, typename common_type<Rep1, Rep2>::type>,
569         boost::is_convertible<Rep2, typename common_type<Rep1, Rep2>::type>
570         >,
571         duration<typename common_type<Rep1, Rep2>::type, Period>
572     >::type
operator *(const duration<Rep1,Period> & d,const Rep2 & s)573     operator*(const duration<Rep1, Period>& d, const Rep2& s)
574     {
575       typedef typename common_type<Rep1, Rep2>::type CR;
576       typedef duration<CR, Period> CD;
577       return CD(CD(d).count()*static_cast<CR>(s));
578     }
579 
580     template <class Rep1, class Period, class Rep2>
581     inline BOOST_CONSTEXPR
582     typename boost::enable_if <
583         mpl::and_ <
584         boost::is_convertible<Rep1, typename common_type<Rep1, Rep2>::type>,
585         boost::is_convertible<Rep2, typename common_type<Rep1, Rep2>::type>
586         >,
587         duration<typename common_type<Rep1, Rep2>::type, Period>
588     >::type
operator *(const Rep1 & s,const duration<Rep2,Period> & d)589     operator*(const Rep1& s, const duration<Rep2, Period>& d)
590     {
591         return d * s;
592     }
593 
594     // Duration /
595 
596     template <class Rep1, class Period, class Rep2>
597     inline BOOST_CONSTEXPR
598     typename boost::disable_if <boost::chrono::detail::is_duration<Rep2>,
599       typename boost::chrono::detail::duration_divide_result<
600         duration<Rep1, Period>, Rep2>::type
601     >::type
operator /(const duration<Rep1,Period> & d,const Rep2 & s)602     operator/(const duration<Rep1, Period>& d, const Rep2& s)
603     {
604         typedef typename common_type<Rep1, Rep2>::type CR;
605         typedef duration<CR, Period> CD;
606 
607       return CD(CD(d).count()/static_cast<CR>(s));
608     }
609 
610     template <class Rep1, class Period1, class Rep2, class Period2>
611     inline BOOST_CONSTEXPR
612     typename common_type<Rep1, Rep2>::type
operator /(const duration<Rep1,Period1> & lhs,const duration<Rep2,Period2> & rhs)613     operator/(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs)
614     {
615         typedef typename common_type<duration<Rep1, Period1>,
616                                    duration<Rep2, Period2> >::type CD;
617         return CD(lhs).count() / CD(rhs).count();
618     }
619 
620     #ifdef BOOST_CHRONO_EXTENSIONS
621     template <class Rep1, class Rep2, class Period>
622     inline BOOST_CONSTEXPR
623     typename boost::disable_if <boost::chrono::detail::is_duration<Rep1>,
624       typename boost::chrono::detail::duration_divide_result2<
625         Rep1, duration<Rep2, Period> >::type
626       >::type
operator /(const Rep1 & s,const duration<Rep2,Period> & d)627     operator/(const Rep1& s, const duration<Rep2, Period>& d)
628     {
629         typedef typename common_type<Rep1, Rep2>::type CR;
630         typedef duration<CR, Period> CD;
631 
632       return static_cast<CR>(s)/CD(d).count();
633     }
634     #endif
635     // Duration %
636 
637     template <class Rep1, class Period, class Rep2>
638     inline BOOST_CONSTEXPR
639     typename boost::disable_if <boost::chrono::detail::is_duration<Rep2>,
640       typename boost::chrono::detail::duration_modulo_result<
641         duration<Rep1, Period>, Rep2>::type
642     >::type
operator %(const duration<Rep1,Period> & d,const Rep2 & s)643     operator%(const duration<Rep1, Period>& d, const Rep2& s)
644     {
645         typedef typename common_type<Rep1, Rep2>::type CR;
646         typedef duration<CR, Period> CD;
647 
648       return CD(CD(d).count()%static_cast<CR>(s));
649     }
650 
651     template <class Rep1, class Period1, class Rep2, class Period2>
652     inline BOOST_CONSTEXPR
653     typename common_type<duration<Rep1, Period1>, duration<Rep2, Period2> >::type
operator %(const duration<Rep1,Period1> & lhs,const duration<Rep2,Period2> & rhs)654     operator%(const duration<Rep1, Period1>& lhs,
655           const duration<Rep2, Period2>& rhs) {
656         typedef typename common_type<duration<Rep1, Period1>,
657                                  duration<Rep2, Period2> >::type CD;
658 
659       return CD(CD(lhs).count()%CD(rhs).count());
660     }
661 
662 
663 //----------------------------------------------------------------------------//
664 //      20.9.3.6 duration comparisons [time.duration.comparisons]             //
665 //----------------------------------------------------------------------------//
666 
667 namespace detail
668 {
669     template <class LhsDuration, class RhsDuration>
670     struct duration_eq
671     {
operator ()boost::chrono::detail::duration_eq672       BOOST_CONSTEXPR bool operator()(const LhsDuration& lhs, const RhsDuration& rhs) const
673         {
674             typedef typename common_type<LhsDuration, RhsDuration>::type CD;
675             return CD(lhs).count() == CD(rhs).count();
676         }
677     };
678 
679     template <class LhsDuration>
680     struct duration_eq<LhsDuration, LhsDuration>
681     {
operator ()boost::chrono::detail::duration_eq682       BOOST_CONSTEXPR bool operator()(const LhsDuration& lhs, const LhsDuration& rhs) const
683         {
684             return lhs.count() == rhs.count();
685         }
686     };
687 
688     template <class LhsDuration, class RhsDuration>
689     struct duration_lt
690     {
operator ()boost::chrono::detail::duration_lt691       BOOST_CONSTEXPR bool operator()(const LhsDuration& lhs, const RhsDuration& rhs) const
692         {
693             typedef typename common_type<LhsDuration, RhsDuration>::type CD;
694             return CD(lhs).count() < CD(rhs).count();
695         }
696     };
697 
698     template <class LhsDuration>
699     struct duration_lt<LhsDuration, LhsDuration>
700     {
operator ()boost::chrono::detail::duration_lt701       BOOST_CONSTEXPR bool operator()(const LhsDuration& lhs, const LhsDuration& rhs) const
702         {
703             return lhs.count() < rhs.count();
704         }
705     };
706 
707 } // namespace detail
708 
709     // Duration ==
710 
711     template <class Rep1, class Period1, class Rep2, class Period2>
712     inline BOOST_CONSTEXPR
713     bool
operator ==(const duration<Rep1,Period1> & lhs,const duration<Rep2,Period2> & rhs)714     operator==(const duration<Rep1, Period1>& lhs,
715           const duration<Rep2, Period2>& rhs)
716     {
717         return boost::chrono::detail::duration_eq<
718             duration<Rep1, Period1>, duration<Rep2, Period2> >()(lhs, rhs);
719     }
720 
721     // Duration !=
722 
723     template <class Rep1, class Period1, class Rep2, class Period2>
724     inline BOOST_CONSTEXPR
725     bool
operator !=(const duration<Rep1,Period1> & lhs,const duration<Rep2,Period2> & rhs)726     operator!=(const duration<Rep1, Period1>& lhs,
727           const duration<Rep2, Period2>& rhs)
728     {
729         return !(lhs == rhs);
730     }
731 
732     // Duration <
733 
734     template <class Rep1, class Period1, class Rep2, class Period2>
735     inline BOOST_CONSTEXPR
736     bool
operator <(const duration<Rep1,Period1> & lhs,const duration<Rep2,Period2> & rhs)737     operator< (const duration<Rep1, Period1>& lhs,
738           const duration<Rep2, Period2>& rhs)
739     {
740         return boost::chrono::detail::duration_lt<
741           duration<Rep1, Period1>, duration<Rep2, Period2> >()(lhs, rhs);
742     }
743 
744     // Duration >
745 
746     template <class Rep1, class Period1, class Rep2, class Period2>
747     inline BOOST_CONSTEXPR
748     bool
operator >(const duration<Rep1,Period1> & lhs,const duration<Rep2,Period2> & rhs)749     operator> (const duration<Rep1, Period1>& lhs,
750           const duration<Rep2, Period2>& rhs)
751     {
752         return rhs < lhs;
753     }
754 
755     // Duration <=
756 
757     template <class Rep1, class Period1, class Rep2, class Period2>
758     inline BOOST_CONSTEXPR
759     bool
operator <=(const duration<Rep1,Period1> & lhs,const duration<Rep2,Period2> & rhs)760     operator<=(const duration<Rep1, Period1>& lhs,
761           const duration<Rep2, Period2>& rhs)
762     {
763         return !(rhs < lhs);
764     }
765 
766     // Duration >=
767 
768     template <class Rep1, class Period1, class Rep2, class Period2>
769     inline BOOST_CONSTEXPR
770     bool
operator >=(const duration<Rep1,Period1> & lhs,const duration<Rep2,Period2> & rhs)771     operator>=(const duration<Rep1, Period1>& lhs,
772           const duration<Rep2, Period2>& rhs)
773     {
774         return !(lhs < rhs);
775     }
776 
777 //----------------------------------------------------------------------------//
778 //      20.9.3.7 duration_cast [time.duration.cast]                           //
779 //----------------------------------------------------------------------------//
780 
781     // Compile-time select the most efficient algorithm for the conversion...
782     template <class ToDuration, class Rep, class Period>
783     inline BOOST_CONSTEXPR
784     typename boost::enable_if <
785       boost::chrono::detail::is_duration<ToDuration>, ToDuration>::type
duration_cast(const duration<Rep,Period> & fd)786     duration_cast(const duration<Rep, Period>& fd)
787     {
788         return boost::chrono::detail::duration_cast<
789           duration<Rep, Period>, ToDuration>()(fd);
790     }
791 
792 } // namespace chrono
793 } // namespace boost
794 
795 #ifndef BOOST_CHRONO_HEADER_ONLY
796 // the suffix header occurs after all of our code:
797 #include <boost/config/abi_suffix.hpp> // pops abi_prefix.hpp pragmas
798 #endif
799 
800 #endif // BOOST_CHRONO_DURATION_HPP
801