Working with NAN

[SMcNeill]

Save as isnan.h:

Code: (Select All)

#include <stdio.h>
#include <math.h>
#include <float.h>

int IsNan (long double n);
IsNan (long double n) {
    return -isnan(n);
    }

And then run the following:

Code: (Select All)

DECLARE CUSTOMTYPE LIBRARY "isnan"

    FUNCTION IsNan% (n AS DOUBLE)

END DECLARE



PRINT IsNan(1 / 0)

PRINT IsNan(2 / 3)

And now you can test for Nan, if you decide to.

(There's also isinf which you'd basically implement the same way if you needed it, which tells you if a value is INF or not.  If you need it as well, and can't sort it out on your own, I'll happily toss it into a simple header file for you.)