Check floats for .nan

[BCS]

Reply to acarion,

> I have this code:
> 
> float number=getFloat();
> assert(number!=float.nan); //this passes

IIRC this will also pass:

assert(float.nan != float.nan);

this is because D used IEEE floating point semantics. Under IEEE a comparison 
with NaN will always be  not equal

If you want to test for nan use "testedValue !<>= 0"* or the isnan function

> assert(to!(char[])(number)!="nan"); //this fails
> writefln(string.toString(number)); //this outputs: "nan"
> writefln( to!(char[])(to!(long)(number)) ); //this generates an error
> What did I do wrong?
> 

* this is the not grater than, less than, or equal to operator.