NAME
fpclassify —
classify real floating type
SYNOPSIS
#include
<math.h>
int fpclassify(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 fpclassify () macro shall classify its
argument value as NaN, infinite, normal, subnormal, zero, or into another
implementation-defined category. First, an argument represented in a format
wider than its semantic type is converted to its semantic type. Then
classification is based on the type of the argument.
RETURN VALUE
The fpclassify () macro shall return the
value of the number classification macro appropriate to the value of its
argument.
ERRORS
No errors are defined.
EXAMPLES
None.
APPLICATION USAGE
None.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
isfinite(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.