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#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);
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.
See attributes(5) for descriptions of the following attributes:
ATTRIBUTE TYPE | ATTRIBUTE VALUE |
MT-Level | MT-Safe |
fpgetround(3C), isnan(3M), attributes(5)