From: Gene Tani <gene.tani@...>
Date: 2005-10-24T21:12:02+09:00
Subject: Re: How to find all the subclasses of a class?

FWIW last summer we made a list of the 10 methods you can use to test
inheritance / mixed-in or extendedness:

Object#kind_of?, #is_a?, #instance_of?, #type (deprecated), #class

Module#ancestors, #included_modules

Class#inherited, #superclass

MyClassname === myobj

Sean O'Halpin wrote:
> Incorporating Robert's suggestions, this is a bit better:
>
> class Module
>   def subclasses
>     classes = []
>     ObjectSpace.each_object(Module) do |m|
>       classes << m if m.ancestors.include? self
>     end
>     classes
>   end
> end
> 
> Regards,
> 
> Sean