WSJT-X/boost/boost/chrono/round.hpp

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1.4 KiB
C++

// boost/chrono/round.hpp ------------------------------------------------------------//
// (C) Copyright Howard Hinnant
// Copyright 2011 Vicente J. Botet Escriba
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
// See http://www.boost.org/libs/chrono for documentation.
#ifndef BOOST_CHRONO_ROUND_HPP
#define BOOST_CHRONO_ROUND_HPP
#include <boost/chrono/duration.hpp>
#include <boost/chrono/duration.hpp>
//#include <boost/chrono/typeof/boost/chrono/chrono.hpp>
namespace boost
{
namespace chrono
{
/**
* rounds to nearest, to even on tie
*/
template <class To, class Rep, class Period>
To round(const duration<Rep, Period>& d)
{
typedef typename common_type<To, duration<Rep, Period> >::type result_type;
result_type diff0;
result_type diff1;
To t0 = duration_cast<To>(d);
To t1 = t0;
if (t0>d) {
--t1;
diff0 = t0 - d;
diff1 = d - t1;
} else {
++t1;
diff0 = d - t0;
diff1 = t1 - d;
}
if (diff0 == diff1)
{
if (t0.count() & 1)
return t1;
return t0;
}
else if (diff0 < diff1)
return t0;
return t1;
}
} // namespace chrono
} // namespace boost
#endif