Is it possible to use std::chrono::duration with Rep type as double? I get compiler error in vs2012 when I try

1
votes

I get a following compiler (vs2012) error:

Error 3 error C2679: binary '+=' : no operator found which takes a right-hand operand of type 'const std::chrono::duration<_Rep,_Period>' (or there is no acceptable conversion) c:\program files (x86)\microsoft visual studio 11.0\vc\include\chrono 749

My definition of duration is:

// Tick interval type in nanoseconds
typedef std::chrono::duration<double, std::ratio<1, 100000000>> tick_interval_type;

Same error when I use float... It only compiles when the Rep type of duration is integer.

Can someone please help?

Edit (more complete log from Output):

c:\program files (x86)\microsoft visual studio 11.0\vc\include\chrono(749): error C2679: binary '+=' : no operator found which takes a right-hand operand of type 'const std::chrono::duration<_Rep,_Period>' (or there is no acceptable conversion) with [ _Rep=double, _Period=std::nano ] c:\program files (x86)\microsoft visual studio 11.0\vc\include\chrono(166): could be 'std::chrono::duration<_Rep,_Period> &std::chrono::duration<_Rep,_Period>::operator +=(const std::chrono::duration<_Rep,_Period> &)' with [ _Rep=__int64, _Period=std::nano ] while trying to match the argument list '(std::chrono::nanoseconds, const std::chrono::duration<_Rep,_Period>)' with [ _Rep=double, _Period=std::nano ] c:\program files (x86)\microsoft visual studio 11.0\vc\include\thread(164) : see reference to function template instantiation 'xtime std::_To_xtime(const std::chrono::duration<_Rep,_Period> &)' being compiled with [ _Rep=double, _Period=std::nano ] c:\dev\projects\revolverx\classes\ticker.h(78) : see reference to function template instantiation 'void std::this_thread::sleep_for(const std::chrono::duration<_Rep,_Period> &)' being compiled with [ _Rep=double, _Period=std::nano ]

2
c++c++11compiler-errorstype-conversionchrono
Are there any more messages in the build log? For example that tells what types was used and what was expected? Please edit your question to include the complete error log. - Some programmer dude
@Joachim Pileborg, my fault, question updated. Hope it helps. - mikeg

2 Answers

6
votes

<chrono> in Visual Studio is broken. It doesn't work with mixed type arithmetic, which, arguably, is one of the main features of <chrono>. You get this error because one of the sides uses __int64 nanos and the other uses double nanos.

I recommend either dropping it in favor of a real C++ implementation, or using Boost.Chrono.

2
votes

Update: I've come upon this question four years after it was originally posted, and I've tested this on Visual Studio 2015. It does compile now. For example:

#include <iostream>
#include <iomanip>
#include <chrono>

int main()
{
    typedef std::chrono::duration<double, std::ratio<1, 100000000>> tick_interval_type;  // Originally posted line
    tick_interval_type tick {0};
    tick += std::chrono::microseconds(3);
    std::cout << std::setprecision(6) << std::fixed << tick.count();
    return 0;
}

Output:

300.000000