Classifies its argument value as NaN, infinite, normal, subnormal or zero.

[Classification]

Mathematical library

[Syntax]

#include <math.h>

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

[Return value]

If the value of the argument is NaN, FP_NAN is returned.

If the value of the argument is infinite, FP_INFINITE is returned.

If the value of the argument is a normal number, FP_NORMAL is returned.

If the value of the argument is a subnormal number, FP_SUBNORMAL is returned.

If the value of the argument is 0, FP_ZERO is returned.

For the value returned by each macro, refer to math.h.

[Description]

This macro classifies its argument value as NaN, infinite, normal, subnormal or zero.

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