If you find yourself facing the dreaded "Indirect modification of overloaded element of $class has no effect" then don't worry too much: there's a clever solution. While you *CANNOT* return by-reference with offsetGet, you can return objects which _also_ implement ArrayAccess...
Example: <?php
// sanity and error checking omitted for brevity
// note: it's a good idea to implement arrayaccess + countable + an
// iterator interface (like iteratoraggregate) as a triplet
class RecursiveArrayAccess implements ArrayAccess {
