From: ruud grosmann <r.grosmann@...>
Date: 2008-09-30T18:24:27+09:00
Subject: extend keyword in class definition

Hi list,

I am reading the book 'design patterns in ruby'. On page 201 I find
this code example:

require 'forwardable'

class WriterDecorator
    extend Forwardable

    def_delegators :@real_writer, :write_line, :rewind, :pos, :close

    def initialize (real_writer)
       @real_writer = real_writer
    end
end


I am a bit surprised by the 'extend Forwardable' line. Can anybody
explain me what this is? Is it the same as 'include Forwardable' or is
it the same as 'class WriterDecorator < Forwardable'?

thanks in advance, Ruud