nan question

[BCS]

Reply to bobef,

> Hello,
> 
> I have a little question.
> This program outputs gggg on dmd 1.21. Yes, I suck at math, but is
> this right (i.e. buggy) or nans must be compared another way?
> ===========================
> 
> import tango.io.Stdout;
> 
> void main()
> {
> double a=double.nan;
> if(a==double.nan) Stdout("1\n");
> else Stdout("g\n");
> if(a is double.nan) Stdout("2\n");
> else Stdout("g\n");
> if(double.nan==double.nan) Stdout("3\n");
> else Stdout("g\n");
> if(double.nan is double.nan) Stdout("4\n");
> else Stdout("g\n");
> }

if you want to check for nan without a function call uses: fpVar !<>= 0