flanerizer.rb

class Object
  def eigenclass
    class << self
      return self
    end
  end
end

class Person
  def hello
    "Hello"
  end
end

module Flanderizer
  def self.included(base)
    def initialize
      super
      self.extend InstanceMethods
    end
  end

  module InstanceMethods
    def hello
      "#{super}-diddly"
    end
  end
end

Person.send :include, Flanderizer

flanders = Person.new

puts flanders.hello # => "Hello-diddly"

puts flanders.class.ancestors.inspect # => [Person, Flanderizer, Object, Kernel];
puts flanders.eigenclass.ancestors.inspect #=> [Flanderizer::InstanceMethods, Person, Flanderizer, Object, Kernel]

##
# This works as well sending it directly to the eigenclass I believe

module Flanderizer
  def self.included(base)
    def initialize
      super
      instance_eval do
        def hello
          "#{super}-diddly"
        end
      end
    end
  end
end