isinf (original) (raw)
The Open Group Base Specifications Issue 6
IEEE Std 1003.1, 2004 Edition
Copyright © 2001-2004 The IEEE and The Open Group, All Rights reserved.
A newer edition of this document exists here
NAME
isinf - test for infinity
SYNOPSIS
`#include <math.h>
int isinf(real-floating
x);
`
DESCRIPTION
[CX]
The functionality described on this reference page is aligned with the ISO C standard. Any conflict between the requirements described here and the ISO C standard is unintentional. This volume of IEEE Std 1003.1-2001 defers to the ISO C standard.
The isinf() macro shall determine whether its argument value is an infinity (positive or negative). First, an argument represented in a format wider than its semantic type is converted to its semantic type. Then determination is based on the type of the argument.
![[Option End]](http://www.opengroup.org/onlinepubs/009695399/images/opt-end.gif)
RETURN VALUE
The isinf() macro shall return a non-zero value if and only if its argument has an infinite value.
ERRORS
No errors are defined.
The following sections are informative.
EXAMPLES
None.
APPLICATION USAGE
None.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
fpclassify(), isfinite(), isnan(), isnormal(), signbit(), the Base Definitions volume of IEEE Std 1003.1-2001 <math.h>
CHANGE HISTORY
First released in Issue 6. Derived from the ISO/IEC 9899:1999 standard.
End of informative text.
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