No C ++ 11 vs vs 2015 pro?

I just installed Visual Studio 2015 RC Pro because I wanted to use C ++ 11 std :: to_string, but it still doesn't seem like 11 ...

std::cout << _cplusplus << std::endl;

      

        
        
        
      

    

Gives me 199711. Shouldn't VS 2015 RC have 11? Or am I doing something wrong? Help rate.

Edit: It seems not entirely clear what I want, so here's more info:

I want to use to_string, a std member in C ++ 11 that turns an int (in this case) into a string.

std::to_string(5);

      

        
        
        
      

    

gives me error: "std has no member to_string"