On Nov 20, 2013, at 12:49 PM, Vicente J. Botet Escriba <vicente.botet@wanadoo.fr> wrote:

Le 20/11/13 13:45, Krzysztof Czainski a écrit :

...

Hello,

The function boost::chrono::floor() is documented: "This function round down the given parameter." Therefore I expect the assert in the following program to pass, but it fails:

#include <boost/chrono/floor.hpp> #include <cassert>

int main() { boost::chrono::nanoseconds const nsec( -1 ); boost::chrono::seconds const sec = boost::chrono::floor<boost::chrono::seconds>(nsec); assert( sec.count() == -1 ); }

Is this intended behavior? If yes, could the docs be updated to clarify this?

Hi,

no, there is a bug with negative numbers.

template <class To, class Rep, class Period> To floor(const duration<Rep, Period>& d) { + if (d<duration<Rep, Period>::zero()) + return duration_cast<To>(d)-To(1); + else return duration_cast<To>(d); }

Please, coul dyou create a ticket so that I don't forget it.

Thanks, Vicente

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#include <chrono> using namespace std::chrono; template <class To, class Rep, class Period> To floor(const duration<Rep, Period>& d) { if (d<duration<Rep, Period>::zero()) return duration_cast<To>(d)-To(1); else return duration_cast<To>(d); } #include <iostream> int main() { using namespace std::literals; std::cout << floor<seconds>(-1000ms).count() << '\n'; } For me outputs: -2 How about this instead: template <class To, class Rep, class Period> To floor(const std::chrono::duration<Rep, Period>& d) { To t = std::chrono::duration_cast<To>(d); if (t > d) --t; return t; } Howard

On Nov 21, 2013, at 4:58 PM, "Vicente J. Botet Escriba" <vicente.botet@wanadoo.fr> wrote:

You are right, as always. I will apply your suggestion.

If I was always right, we wouldn't be discussing this bug. ;-) There may be optimization opportunities in Kris' suggestion, I haven't investigated that. Howard

2013/11/21 Krzysztof Czainski <1czajnik@gmail.com>

2013/11/21 Howard Hinnant <howard.hinnant@gmail.com>

...

On Nov 20, 2013, at 12:49 PM, Vicente J. Botet Escriba < vicente.botet@wanadoo.fr> wrote:

...

Le 20/11/13 13:45, Krzysztof Czainski a écrit :

...

Hello,

The function boost::chrono::floor() is documented: "This function round down the given parameter." Therefore I expect the assert in the following program to pass, but it fails:

#include <boost/chrono/floor.hpp> #include <cassert>

int main() { boost::chrono::nanoseconds const nsec( -1 ); boost::chrono::seconds const sec = boost::chrono::floor<boost::chrono::seconds>(nsec); assert( sec.count() == -1 ); }

Is this intended behavior? If yes, could the docs be updated to clarify this?

Hi,

no, there is a bug with negative numbers.

template <class To, class Rep, class Period> To floor(const duration<Rep, Period>& d) { + if (d<duration<Rep, Period>::zero()) + return duration_cast<To>(d)-To(1); + else return duration_cast<To>(d); }

Please, coul dyou create a ticket so that I don't forget it.

Thanks, Vicente

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#include <chrono>

using namespace std::chrono;

template <class To, class Rep, class Period> To floor(const duration<Rep, Period>& d) { if (d<duration<Rep, Period>::zero()) return duration_cast<To>(d)-To(1); else return duration_cast<To>(d); }

#include <iostream>

int main() { using namespace std::literals; std::cout << floor<seconds>(-1000ms).count() << '\n'; }

For me outputs:

-2

How about this instead:

template <class To, class Rep, class Period> To floor(const std::chrono::duration<Rep, Period>& d) { To t = std::chrono::duration_cast<To>(d); if (t > d) --t; return t; }

Howard

Ticket #9419 created.

I think it's a bit more complicated. Doesn't Howard's version return -2 as well?

Oh, I get it now, clever ;) Regards, Kris