From: Jim Weirich <jweirich@...>
Date: 2003-04-08T10:03:45+09:00
Subject: Re: @@class variables and subclasses

On Mon, 2003-04-07 at 20:42, Ryan Pavlik wrote:
> OK, this has been causing me problems:
> 
>     class A
>         @@index = Index.new(...)
>     end #c:A
> 
> 
>     class B < A
>         @@index = Index.new(...)
>     end #c:B

Try this ...

  class A
    class << self
      attr_accessor :index
    end

    def f
      self.class.index = Index.new
      # or
      A.index
    end
  end

And if B inherits from A, it A.index and B.index are independent.

-- 
-- Jim Weirich     jweirich@one.net    http://w3.one.net/~jweirich
---------------------------------------------------------------------
"Beware of bugs in the above code; I have only proved it correct, 
not tried it." -- Donald Knuth (in a memo to Peter van Emde Boas)