class(3C)

NAME
     fpclassify, fpclassifyf, fpclassifyl, isfinite, isfinitef, isfinitel,
     isunordered, isunorderedf, isunorderedl, isinf, isinff, isinfl, isnormal,
     isnormalf, isnormall - classification macros

SYNOPSIS
     #include <math.h>

     int fpclassify(x);
     int isfinite(x);
     int isinf(x);
     int isnormal(x);
     int isunordered(x);

DESCRIPTION
     These routines are not available for programs compiled with the O32 ABI.

     Functions in the standard math library (libm.a) are referred to as -lm
     versions. Those in mathx library (libmx.a) are referred to as -lmx
     versions, and those in the the BSD math library (libm43.a) are referred
     to as -lm43 versions.

     The fpclassify macro returns the value of the number classification macro
     appropriate to the value of its argument.

     The isinfinite macro returns a non-zero value if and only if its argument
     has a finite value.

     The isinf macro returns a nonzero value if its argument has an infinite
     value.

     The isnormal macro returns a nonzero value if its argument has a normal
     value.

     The isunordered macro returns 1 if its arguments are unordered and
     returns 0 otherwise.

     These macros are implemented in terms of ordinary functions depending on
     the argument used; for example, if x is a float value, the macro is
     redefined as fpclassifyf.  If x is double, the macro is redefined as
     fpclassify.  If x is long double, the macro is redefined as fpclassifyl.

NOTES
     Long double operations on this system are only supported in round to
     nearest rounding mode (the default). The system must be in round to
     nearest rounding mode when calling any of the long double functions, or
     incorrect answers will result.

RETURN VALUES
     The -lm and -lmx versions always return the default Quiet NaN and set
     errno to EDOM when a NaN is used as an argument.  A NaN argument usually
     causes the -lm43 versions to return the same argument.  The -lm43
     versions never set errno.

     See matherr(3M) for a description of error handling for -lmx functions.

SEE ALSO
     math(3M), frexp(3C), isnan(3C), matherr(3M)