From: Chad Perrin <code@...>
Date: 2011-12-06T05:01:15+09:00
Subject: Re: black magical hash element vivification

On Tue, Dec 06, 2011 at 01:39:54AM +0900, Adam Prescott wrote:
> D'oh! Strike that, it's behaving as expected, it's just hidden beneath an
> extra layer of oddness.
> 
> >> foo = Hash.new(Hash.new)
> => {}
> >> foo[3][2] = true
> => true
> 
> There's no assignment for the top-level hash. So the default hash object
> specified in Hash.new(Hash.new) has been modified, but you can't see it
> directly because you don't do, e.g., foo[3]=.

That, for me, is *very* surprising behavior.  I would think that it
should treat the default as though it exists, even when not referencing
it directly.