Determines whether its argument value is normal (neither zero, subnormal, infinite, nor NaN).

[Classification]

Mathematical library

[Syntax]

#include <math.h>

int isnormal(real-floating x); (C99)

[Return value]

If the argument is a normal number, a value other than 0 is returned.

If the argument is 0, a subnormal number, infinite, or NaN, 0 is returned.

[Description]

This macro determines whether its argument value is normal (neither zero, subnormal, infinite, nor NaN).

If a type other than the floating-point type is passed to the argument, correct operation is not guaranteed.