1 | // min_time_point.cpp ----------------------------------------------------------// |
2 | |
3 | // Copyright 2008 Howard Hinnant |
4 | // Copyright 2008 Beman Dawes |
5 | // Copyright 2009 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 | This code was extracted by Vicente J. Botet Escriba from Beman Dawes time2_demo.cpp which |
12 | 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 | #include <boost/chrono/typeof/boost/chrono/chrono.hpp> |
30 | #include <boost/type_traits.hpp> |
31 | |
32 | #include <iostream> |
33 | |
34 | using namespace boost::chrono; |
35 | |
36 | template <class Rep, class Period> |
37 | void print_duration(std::ostream& os, duration<Rep, Period> d) |
38 | { |
39 | os << d.count() << " * " << Period::num << '/' << Period::den << " seconds\n" ; |
40 | } |
41 | |
42 | namespace my_ns { |
43 | // Example min utility: returns the earliest time_point |
44 | // Being able to *easily* write this function is a major feature! |
45 | template <class Clock, class Duration1, class Duration2> |
46 | inline |
47 | typename boost::common_type<time_point<Clock, Duration1>, |
48 | time_point<Clock, Duration2> >::type |
49 | min BOOST_PREVENT_MACRO_SUBSTITUTION (time_point<Clock, Duration1> t1, time_point<Clock, Duration2> t2) |
50 | { |
51 | return t2 < t1 ? t2 : t1; |
52 | } |
53 | } |
54 | void test_min() |
55 | { |
56 | #if 1 |
57 | typedef time_point<system_clock, |
58 | boost::common_type<system_clock::duration, seconds>::type> T1; |
59 | typedef time_point<system_clock, |
60 | boost::common_type<system_clock::duration, nanoseconds>::type> T2; |
61 | typedef boost::common_type<T1, T2>::type T3; |
62 | /*auto*/ T1 t1 = system_clock::now() + seconds(3); |
63 | /*auto*/ T2 t2 = system_clock::now() + nanoseconds(3); |
64 | /*auto*/ T3 t3 = (my_ns::min)(t1, t2); |
65 | #else |
66 | BOOST_AUTO(t1, system_clock::now() + seconds(3)); |
67 | BOOST_AUTO(t2, system_clock::now() + nanoseconds(3)); |
68 | BOOST_AUTO(t3, (min)(t1, t2)); |
69 | #endif |
70 | print_duration(os&: std::cout, d: t1 - t3); |
71 | print_duration(os&: std::cout, d: t2 - t3); |
72 | } |
73 | |
74 | int main() |
75 | { |
76 | test_min(); |
77 | return 0; |
78 | } |
79 | |
80 | |