Re: Nim source equivalent to C #define

[mratsim]

I use a [nim.cfg in 
Arraymancer](https://github.com/mratsim/Arraymancer/blob/7edf23662328c059cd22be4cd08c00556321e4d1/nim.cfg#L43):
    
    
    @if cudnn:
      define:"cuda"
    @end
    
    
    Run