isnan(3M) isnan(3M) NAME isnan() - floating-point test for NaN SYNOPSIS floating-type DESCRIPTION The macro determines whether its argument is a NaN. The argument must be of floating type. For HP Integrity servers, the argument can be any floating type. For PA-RISC, the argument must be either or The macro implements the functionality recommended by the IEEE-754 standard for floating-point arithmetic. The macro replaces the and functions, which are obsolete and are no longer supported. USAGE To use the macro, compile either with the default option or with the and options. Make sure your program includes Link in the math library by specifying on the compiler or linker command line. RETURN VALUE The macro returns a nonzero value if and only if its argument has a NaN value. The macro raises no floating-point exceptions. ERRORS No errors are defined. EXAMPLES Take certain actions if is not a NaN: SEE ALSO fpclassify(3M), isfinite(3M), isinf(3M), isnormal(3M), signbit(3M), math(5). STANDARDS CONFORMANCE isnan(3M)