isunordered()

Determine whether two floating-point numbers are unordered

Synopsis:

#include <math.h>

#define isunordered( x, y ) ...

Arguments:

x, y: The floating-point values that you want to check.

Library:

libm

Use the -l m option to qcc to link against this library.

Description:

The isunordered() macro determines whether the given floating-point numbers are unordered (i.e., one or both are NaN and thus can't be meaningfully compared with each other).

Returns:

1 if the arguments are unordered, or 0 otherwise. If x or y is NaN, this function returns 1.

Classification:

ANSI, POSIX 1003.1

Safety:
Cancellation point	No
Interrupt handler	No
Signal handler	No
Thread	Yes