fpclassify - classify real floating type
int fpclassify(real-floating x);
[CX] The functionality described on this reference page is aligned with the ISO C standard. Any conflict between the requirements described here and the ISO C standard is unintentional. This volume of POSIX.1-2017 defers to the ISO C standard.
The fpclassify() macro shall classify its argument value as NaN, infinite, normal, subnormal, zero, or into another implementation-defined category. First, an argument represented in a format wider than its semantic type is converted to its semantic type. Then classification is based on the type of the argument.
The fpclassify() macro shall return the value of the number classification macro appropriate to the value of its argument.
No errors are defined.
isfinite, isinf, isnan, isnormal, signbit
First released in Issue 6. Derived from the ISO/IEC 9899:1999 standard.
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