In search of cbrt() ...

[Doug Gwyn]

In article <4502 at goanna.cs.rmit.oz.au> ok at goanna.cs.rmit.oz.au (Richard A. O'Keefe) writes:
>> However, if all it does is extract a cube-root, it's trivial to emulate:
>> 	#include <math.h>
>> 	#define cubrt(x) pow(x,1.0/3.0)
>That doesn't quite do the job.  cbrt(-8.0) is -2.0, but pow(-8.0, 1.0/3.0)
>prints "DOMAIN error" and returns 0.0.

Obviously.  And there are also complex cube roots, etc.  I assumed
that the operand was non-negative for simplicity, since it might be
known to be so in the particular application.