1// boost/chrono/round.hpp ------------------------------------------------------------//
2
3// (C) Copyright Howard Hinnant
4// Copyright 2011 Vicente J. Botet Escriba
5
6// Distributed under the Boost Software License, Version 1.0. (See accompanying
7// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
8
9// See http://www.boost.org/libs/chrono for documentation.
10
11#ifndef BOOST_CHRONO_ROUND_HPP
12#define BOOST_CHRONO_ROUND_HPP
13
14#include <boost/chrono/duration.hpp>
15#include <boost/chrono/duration.hpp>
16//#include <boost/chrono/typeof/boost/chrono/chrono.hpp>
17
18namespace boost
19{
20 namespace chrono
21 {
22
23 /**
24 * rounds to nearest, to even on tie
25 */
26 template <class To, class Rep, class Period>
27 To round(const duration<Rep, Period>& d)
28 {
29 typedef typename common_type<To, duration<Rep, Period> >::type result_type;
30 result_type diff0;
31 result_type diff1;
32
33 To t0 = duration_cast<To>(d);
34 To t1 = t0;
35 if (t0>d) {
36 --t1;
37 diff0 = t0 - d;
38 diff1 = d - t1;
39 } else {
40 ++t1;
41 diff0 = d - t0;
42 diff1 = t1 - d;
43 }
44
45 if (diff0 == diff1)
46 {
47 if (t0.count() & 1)
48 return t1;
49 return t0;
50 }
51 else if (diff0 < diff1)
52 return t0;
53 return t1;
54 }
55
56 } // namespace chrono
57} // namespace boost
58
59#endif
60

source code of boost/libs/chrono/include/boost/chrono/round.hpp