man.bsd.lv manual page server

Manual Page Search Parameters

FPCLASSIFY(3) Library Functions Manual FPCLASSIFY(3)

fpclassify, isfinite, isinf, isnan, isnormalclassify a floating-point number

#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 () macro takes an argument of x and returns one of the following manifest constants.
Indicates that x is an infinite number.
Indicates that x is not a number (NaN).
Indicates that x is a normalized number.
Indicates that x is a denormalized number.
Indicates that x is zero (0 or -0).

The () macro returns a non-zero value if and only if its argument has a finite (zero, subnormal, or normal) value. The (), isnan(), and () macros return non-zero if and only if x is an infinity, NaN, or a non-zero normalized number, respectively.

The symbol () is provided as an alias to () for compatibility, and its use is deprecated. Similarly, () and () are deprecated versions of isfinite().

isgreater(3), math(3), signbit(3)

The fpclassify(), isfinite(), isinf(), isnan(), and isnormal() macros conform to ISO/IEC 9899:1999 (“ISO C99”).

The fpclassify(), isfinite(), isinf(), isnan(), and isnormal() macros were added in DragonFly 1.3. 3BSD introduced isinf() and isnan() functions, which accepted double arguments; these have been superseded by the macros described above.

May 28, 2019 DragonFly-5.6.1