FPCLASSIFY(3) | Library Functions Manual | FPCLASSIFY(3) |
fpclassify
,
isfinite
, isinf
,
isnan
, isnormal
—
classify a floating-point number
Math Library (libm, -lm)
#include
<math.h>
int
fpclassify
(real-floating
x);
int
isfinite
(real-floating
x);
int
isinf
(real-floating
x);
int
isnan
(real-floating
x);
int
isnormal
(real-floating
x);
The
fpclassify
()
macro takes an argument of x and returns one of the
following manifest constants.
FP_INFINITE
FP_NAN
FP_NORMAL
FP_SUBNORMAL
FP_ZERO
The
isfinite
()
macro returns a non-zero value if and only if its argument has a finite
(zero, subnormal, or normal) value. The
isinf
(),
isnan
(),
and
isnormal
()
macros return non-zero if and only if x is an
infinity, NaN, or a non-zero normalized number, respectively.
The fpclassify
(),
isfinite
(), isinf
(),
isnan
(), and isnormal
()
macros conform to ISO/IEC 9899:1999
(“ISO C99”).
3BSD introduced
isinf
() and isnan
()
functions, which accepted double arguments; these have
been superseded by the macros described above.
December 11, 2006 | macOS 14.6 |