_fpclass, _fpclassf
The latest version of this topic can be found at _fpclass, _fpclassf.
Returns a value indicating the floating-point classification of the argument.
Syntax
int _fpclass(
double x
);
int _fpclassf(
float x
); /* x64 only */
Parameters
x
The floating-point value to test.
Return Value
The _fpclass and _fpclassf functions return an integer value that indicates the floating-point classification of the argument x. The classification may have one of the following values, defined in <float.h>.
| Value | Description |
|---|---|
_FPCLASS_SNAN |
Signaling NaN |
_FPCLASS_QNAN |
Quiet NaN |
_FPCLASS_NINF |
Negative infinity ( –INF) |
_FPCLASS_NN |
Negative normalized non-zero |
_FPCLASS_ND |
Negative denormalized |
_FPCLASS_NZ |
Negative zero ( – 0) |
_FPCLASS_PZ |
Positive 0 (+0) |
_FPCLASS_PD |
Positive denormalized |
_FPCLASS_PN |
Positive normalized non-zero |
_FPCLASS_PINF |
Positive infinity (+INF) |
Remarks
The _fpclass and _fpclassf functions are Microsoft specific. They are similar to fpclassify, but return more detailed information about the argument. The _fpclassf function is only available when compiled for the x64 platform.
Requirements
| Function | Required header |
|---|---|
_fpclass |
<float.h> |
For more compatibility and conformance information, see Compatibility.