2006/6/4, Elliot Temple <curi / curi.us>:
>
> On Jun 3, 2006, at 6:17 PM, Ray Baxter wrote:
>
> > Alder Green wrote:
> >
> >> For example: check if integer i is a power of 2, with an
> >> expression no
> >> more than 13 characters long.
> >> Solution: (i & (i - 1))
> >
> > 0 is a power of 2?
>
> 2^negative_infinity

Wow, this actuall works in Ruby:

irb(main):004:0> -1.0/0
=> -Infinity
irb(main):007:0> 2 ** (-1.0/0)
=> 0.0

> add a special case if you like.

... and violate the 13 character constraint. :-)

robert

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