From: ts <decoux@...>
Date: 2003-04-14T23:06:44+09:00
Subject: Re: [Q] A class, that knows about it's instances + Sets

>>>>> "C" == Chris Pine <nemo@hellotree.com> writes:

C> My 5 minute solution (a bit of a hack) required class methods, which are
C> *not* inherited when you include a module into a class, so I don't think it
C> would work in your case. 

  extend Module

 a stupid example with 1.8

pigeon% cat b.rb
#!/usr/bin/ruby
module Viv
   def create(*args, &block)
      obj = allocate
      if ! const_defined?(:INSTANCES)
         const_set(:INSTANCES,[])
      end
      const_get(:INSTANCES) << obj
      obj.init (*args, &block)
      obj
   end

   def self.extend_object(a)
      a.instance_eval {define_method(:initialize) { raise "error"}}
      super
   end
end

class A
   extend Viv
   def init(a)
      @a = a
   end
end

A.new rescue p $!
p A.create(12)

pigeon% 

pigeon% ruby b.rb
#<RuntimeError: error>
#<A:0x401ab678 @a=12>
pigeon% 



Guy Decoux