[Dave]
>
> > One of the listed methods of Fixnums and Bignums is "~".  What does it
> > do?  It's not a method of Integers apparently.
> 
> Bit invert:
> 
>   http://www.rubycentral.com/book/ref_c_fixnum.html#Bitoperations

Geez Louise... and of course I knew about that before, but had a little
brain outage and couldn't make sense of seeing it listed with the
methods.  So I was playing with irb, trying to get 3.~ and stuff like
that to work.

operations are methods. operations are methods. right. got it.

Thanks.

  -- Mark