Composition or Decoration?

gistfile1.rb

class Decorator
  def self.decorate(subject)
    subject.define_singleton_method(:with) do |delegate|
      @delegate_list ||= []
      @delegate_list << delegate
    end

    subject.define_singleton_method(:method_missing) do |meth, *args, &block|
      begin
        @delegate_list.find do |delegate|
          delegate.respond_to?(meth)
        end.send(meth)
      rescue
        super(meth, *args, &block)
      end
    end
    subject
  end
end