ISNAND(3C)ISNAND(3C)NAME
isnand, isnanf, finite, fpclass, unordered - determine type of float‐
ing-point number
SYNOPSIS
#include <ieeefp.h>
int isnand(double dsrc);
int isnanf(float fsrc);
int finite(double dsrc);
fpclass_t fpclass(double dsrc);
int unordered(double dsrc1, double dsrc2);
DESCRIPTION
The isnand() and isnanf() functions return TRUE (1) if the argument
dsrc or fsrc is a NaN; otherwise they return FALSE (0).
The fpclass() function returns one of the following classes to which
dsrc belongs:
FP_SNAN
signaling NaN
FP_QNAN
quiet NaN
FP_NINF
negative infinity
FP_PINF
positive infinity
FP_NDENORM
negative denormalized non-zero
FP_PDENORM
positive denormalized non-zero
FP_NZERO
negative zero
FP_PZERO
positive zero
FP_NNORM
negative normalized non-zero
FP_PNORM
positive normalized non-zero
The finite() function returns TRUE (1) if the argument dsrc is neither
infinity nor NaN; otherwise it returns FALSE (0).
The unordered() function returns TRUE (1) if one of its two arguments
is unordered with respect to the other argument. This is equivalent to
reporting whether either argument is NaN. If neither argument is NaN,
FALSE (0) is returned.
None of these functions generates an exception, even for signaling
NaNs.
RETURN VALUES
See DESCRIPTION.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
┌───────────────┬─────────────────┐
│ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├───────────────┼─────────────────┤
│MT-Level │ MT-Safe │
└───────────────┴─────────────────┘
SEE ALSOfpgetround(3C), isnan(3M), attributes(5)
Jun 15, 2004 ISNAND(3C)