From: why the lucky stiff <ruby-talk@...>
Date: 2003-07-05T00:31:36+09:00
Subject: Re: purpose of replace method

Anders Borch (spam@deck.dk) wrote:
> >
> >I believe he wants #become.
> >
> 
> yep, but that's not in Object either.
> 

See [ruby-core:1164].  I guess `become' was added, then disappeared.
Cited as being too dangerous.

I think it's a possible and valuable feature for Ruby, but some
disagree.  You can actually get away with doing some of the same tricks
with a Delegator.  If you check out Delegator and WeakRef classes,
you'll see some semblance of pointers.

Here's an initial stab at a WeakRef#become, which serves proper in most
of my cases.

  require 'weakref'

  class WeakRef
      def become(obj)
          ID_MAP.delete self.__id__
          initialize(obj)
          self
      end
  end

Example usage:

  >> a = [1, 2]
  >> b = [3, 4]
  >> c = WeakRef.new a
  >> puts c.inspect
  [1, 2]
  >> c.become b
  >> puts c.inspect
  [3, 4]

Also see ObjectSpace#_id2ref.
  
_why