Your weak reference sounds very much like JNI. In our case we could eventually do it but we pretty much do not have something to hook into the garbage collection to get rid of otherwise no longer used objects.

A question from my side is whether you want some template/generic solution here or something else. In your example code you had stdClsss as base class but you must remember that not all PHP classes derive from that class. Actually we have no common base class at all. Which basically brings us back to the template/generic solution.

What we could do is provide a function that creates a class derived from SplObjectStorage that only works on a given class or interface. Would that solve what you want?

Pardon my ignorance but I have no idea what you mean when you say JNI.

The main functionality I'm looking for is to simply (from a PHP point of view) be able to link objects to /any/ existing object without having to do or worry about the following:

   1. Amend the existing class declarations.
   2. Having to manually implement some kind of 'garbage collection' when your holding object is the only object left with references to the base objects. As far as I can see this can not be done from within a php script.

Just thinking off the top of my head but this could probably be linked in with the recent __toHash() debate on the internals list. If the __toHash() functionality was available along with an object_hash_exists($hashString) function then the functionality could be implemented from within a php script. You wouldn't have automatic GC but you could then provide a cleanUp() method that you could call to check that the object hashes exist and then act accordingly. Also depending on how the GC works internally you might also be able to provide a register_gc_function($callback) so that the cleanUp() method get called whenever the PHP GC is actioned.

As for the example I posted, I was using stdClsss as a way to ensure that only objects are allowed to be passed to the class methods. Off topic but is there a better way to do this or should I just leave out the type hinting and do an is_object($foo) check within the method?

I have already created a php land class that extends SplObjectStorage that only works on given classes or interfaces, however this does not help with the request in hand, although it is useful in its own right.

Seems that what you are looking for is:

https://github.com/colder/php-weakref