In article <2003421501.202667 / PADD>,
Austin Ziegler  <austin / halostatue.ca> wrote:
>Uninheritable provides a simple way to make a class uninheritable
>(unable to be subclassed from). While the technique to do this is
>not difficult, neither is it immediately obvious, and there is no
>standard exception for this.
>
>  require 'uninheritable'
>
>  class A
>    extend Uninheritable
>  end
>
>  class B < A; end # => raises a TypeError

Interesting...

>
>Installation of "Uninheritable" requires Phil Thomson's installpkg.
>Thanks to David Black for his assistance with this on #ruby-talk.

Since it isn't too big I've taken to including the installpkg.rb in the 
/lib directory of my packages.  Then your install.rb script does a 'require 
"lib/installpkg.rb"' and it gets installed with the rest of your package 
thereby installing installpkg.rb onto more and more machines...

It would probably be a good idea to do a check to see if it's already 
installed.

Phil