NAME
isfinite — test
for finite value
SYNOPSIS
#include
<math.h>
int isfinite(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 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.
EXAMPLES
None.
APPLICATION USAGE
None.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
fpclassify(3), isinf(3), isnan(3), isnormal(3), signbit(3)
XBD <math.h>
CHANGE HISTORY
First released in Issue 6. Derived from the ISO/IEC 9899:1999 (“ISO C99”) standard.