As far as purity goes, pow2 *is* pure. ...
According to http://en.wikipedia.org/wiki/Pure_function it's not:"The [pure] function always evaluates the same result value given the same argument value(s)"
As far as purity goes, pow2 *is* pure. ...
According to http://en.wikipedia.org/wiki/Pure_function it's not:"The [pure] function always evaluates the same result value given the same argument value(s)"