ISNAN(3M) Mathematical Library Functions ISNAN(3M)
NAME
isnan - test for NaN
SYNOPSIS
cc [
flag... ]
file...
-lm [
library... ]
#include <math.h>
int isnan(
double x);
c99 [
flag... ]
file...
-lm [
library... ]
#include <math.h>
int isnan(
real--floating x);
DESCRIPTION
In C90 mode, the
isnan() function tests whether
x is NaN.
In C99 mode, the
isnan() macro determines whether its argument value
is NaN. First, an argument represented in a format wider than its
semantic type is converted to its semantic type. The determination is
then based on the type of the argument.
RETURN VALUES
Both the
isnan() function and macro return non-zero if and only if
x is NaN.
ERRORS
No errors are defined.
WARNINGS
In C99 mode, the practice of explicitly supplying a prototype for
isnan() after the line
#include <math.h>
is obsolete and will no longer work.
ATTRIBUTES
See
attributes(7) for descriptions of the following attributes:
+----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+----------------------------+-----------------------------+
|Interface Stability | Standard |
+----------------------------+-----------------------------+
|MT-Level | MT-Safe |
+----------------------------+-----------------------------+
SEE ALSO
math.h(3HEAD),
fpclassify(3M),
isfinite(3M),
isinf(3M),
isnormal(3M),
signbit(3M),
attributes(7),
standards(7)SunOS 5.11 July 12, 2006 ISNAN(3M)
