1// xtime.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/*
11This code was extracted by Vicente J. Botet Escriba from Beman Dawes time2_demo.cpp which
12was derived by Beman Dawes from Howard Hinnant's time2_demo prototype.
13Many thanks to Howard for making his code available under the Boost license.
14The original code was modified to conform to Boost conventions and to section
1520.9 Time utilities [time] of the C++ committee's working paper N2798.
16See http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2798.pdf.
17
18time2_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/chrono.hpp>
30#include <boost/type_traits.hpp>
31
32#include <iostream>
33
34using namespace boost::chrono;
35
36// Example round_up utility: converts d to To, rounding up for inexact conversions
37// Being able to *easily* write this function is a major feature!
38template <class To, class Rep, class Period>
39To
40round_up(duration<Rep, Period> d)
41{
42 To result = duration_cast<To>(d);
43 if (result < d)
44 ++result;
45 return result;
46}
47
48// demonstrate interaction with xtime-like facility:
49
50// msvc defines ::xtime in <mutex>, so we use xtime_
51struct xtime_
52{
53 long sec;
54 unsigned long usec;
55};
56
57template <class Rep, class Period>
58xtime_
59to_xtime_truncate(duration<Rep, Period> d)
60{
61 xtime_ xt;
62 xt.sec = static_cast<long>(duration_cast<seconds>(d).count());
63 xt.usec = static_cast<long>(duration_cast<microseconds>(d - seconds(xt.sec)).count());
64 return xt;
65}
66
67template <class Rep, class Period>
68xtime_
69to_xtime_round_up(duration<Rep, Period> d)
70{
71 xtime_ xt;
72 xt.sec = static_cast<long>(duration_cast<seconds>(d).count());
73 xt.usec = static_cast<unsigned long>(round_up<microseconds>(d - seconds(xt.sec)).count());
74 return xt;
75}
76
77microseconds
78from_xtime(xtime_ xt)
79{
80 return seconds(xt.sec) + microseconds(xt.usec);
81}
82
83void print(xtime_ xt)
84{
85 std::cout << '{' << xt.sec << ',' << xt.usec << "}\n";
86}
87
88void test_with_xtime()
89{
90 std::cout << "test_with_xtime\n";
91 xtime_ xt = to_xtime_truncate(d: seconds(3) + milliseconds(251));
92 print(xt);
93 milliseconds ms = duration_cast<milliseconds>(fd: from_xtime(xt));
94 std::cout << ms.count() << " milliseconds\n";
95 xt = to_xtime_round_up(d: ms);
96 print(xt);
97 xt = to_xtime_truncate(d: seconds(3) + nanoseconds(999));
98 print(xt);
99 xt = to_xtime_round_up(d: seconds(3) + nanoseconds(999));
100 print(xt);
101}
102
103
104int main()
105{
106 test_with_xtime();
107 return 0;
108}
109
110

source code of boost/libs/chrono/example/xtime.cpp