#!/usr/bin/env ruby
# This code comes from http://ruby-it.org/pages/Mixin
# Check the page for copyright notice and explanations



module M
 def foo
  "foo!"
 end
end
class C
 include M
end
C.new.foo #=> "foo!"

>> module Vendibile
>>  def stringa_prezzo
>>   prezzo.to_s+" euro"
>>  end
>>  def prezzo_ivato
>>   prezzo+ (prezzo*20)/100
>>  end
>>  def to_s
>>   self.class.inspect+": "+stringa_prezzo
>>  end
>> end
=> nil
>> class Lampada
>>  include Vendibile
>>  def prezzo() 100 end
>> end
=> nil
>> l=Lampada.new
=> Lampada: 100 euro
>> l.prezzo_ivato
=> 120