On Nov 8, 4:39 pm, Greg Weeks <gregwe... / shaw.ca> wrote:
> >   class Person
> >     include ActiveRecord::Validations
>
> (I assume that "include" above is a typo for "extend".)

Nope, only because (as seen in my earlier post)
ActiveRecord::Validations has a hook method that detects when it has
been included in something else, and automagically calls 'extend's
that something else with the methods in the
ActiveRecord::Validations::ClassMethods module.