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 IEEE Std 1003.1-2001 (“POSIX.1”) 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), the Base Definitions volume of IEEE Std 1003.1-2001 (“POSIX.1”) <math.h>
CHANGE HISTORY
First released in Issue 6. Derived from the ISO/IEC 9899:1999 (“ISO C99”) standard.
End of informative text. footer end