From: Stephen White <spwhite@...>
Date: 2001-08-23T06:51:14+09:00
Subject: [ruby-talk:20126] Possible RCR - attr_extern for Mix-Ins

It might be nice if there were something like:

  module Comparable
    attr_extern :<=>
  end

  module Enumerable
    attr_extern :each, :<=>
  end

to document the dependence on external code.

This would also provide a way for mix-ins to have their own name-space.
They can then use public/private to control how they merge into a class.