isnan(3M) Mathematical Library Functions isnan(3M)NAMEisnan - 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is obsolete and will no longer work.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(5) for descriptions of the following attributes:
┌─────────────────────────────┬─────────────────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├─────────────────────────────┼─────────────────────────────┤
│Interface Stability │Standard │
├─────────────────────────────┼─────────────────────────────┤
│MT-Level │MT-Safe │
└─────────────────────────────┴─────────────────────────────┘
SEE ALSOfpclassify(3M), isfinite(3M), isinf(3M), isnormal(3M), math.h(3HEAD),
signbit(3M), attributes(5), standards(5)SunOS 5.10 12 Jul 2006 isnan(3M)
