Um. No. An important design goal of Pixie was that you should be able to throw any object (for only slightly limited values of 'any') you like at pixie and the pixie would do its magic and store it. We already handle hash based objects quite handily, and array based objects that implement an _oid can be dealt with as 'top level' objects. If they don't implement _oid they can only be used in the contents of objects, subject to certain limitations.

In general, the objects that are stored should never need to know that they've been persisted (they may want to know, but that shouldn't be a requirement). For instance, I have objects stored in Pixie, working quite happily, that have timestamps implemented using Time::Piece. Getting that to work too precisely no extra work on my part (apart from the work of implementing Pixie in the first place of course). Of course, there are CPAN modules that will need work to handle -- Set::Object, for instance, is a very handy class which can't be directly persisted by Pixie (which uses Data::Dumper to do a lot of its heavy lifting). However, we have a way forward, using $Data::Dumper::Freezer and Data::Dumper::Toaster, which should make even 'pathological' objects tractable to being stored (though maybe not to being 'top level' objects), and which we can use to provide hooks to users who need them.

Hmm... maybe I should prepare a proper medition. Until then, you can take a look at the current (horribly undocumented) state of the Pixie art on CPAN.