isfinite man page

Prolog

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isfinite — test for finite value

Synopsis

#include <math.h>

int isfinite(real-floating x);

Description

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 POSIX.1‐2008 defers to the ISO C standard.

The isfinite() macro shall determine whether its argument has a finite value (zero, subnormal, or normal, and not infinite or NaN). 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.

Return Value

The isfinite() macro shall return a non-zero value if and only if its argument has a finite value.

Errors

No errors are defined.

The following sections are informative.

See Also

fpclassify(), isinf(), isnan(), isnormal(), signbit()

The Base Definitions volume of POSIX.1‐2008, <math.h>

Info

2013 IEEE/The Open Group POSIX Programmer's Manual