Jifty's land grab on the '0' package is irksome. There's only one other similar package and that's "\0" and it's impossible(?) to install methods into. The real problem is that some objects would prefer to be thought of as "not an object" and bad code out there uses ref() to decide this.
I figure it'd be better to be able to have a general mechanism where ref() can return false for any given object should that behaviour be desired.
I initially thought of installing &ref to override the builtin. This works as long as you do it before your calling code is compiled but not after. Oops.
Instead of that, the opcode pp_ref itself can be overridden by swapping in our own function into PL_ppaddr[OP_REF]. Woot! That'd work and this would mean objects of *any* class can request funky behaviour for ref( $obj ).
Cool. Package 0 isn't needed anymore (only if this wrapper gets written).