Well, the point of the OP goes further than that. Two Big Questions are (a) what to do with the non-owning back references (such as backref going up the owning

Well, the point of the OP goes further than that. Two Big Questions are (a) what to do with the non-owning back references (such as backref going up the owning tree) - for this 'soft' pointers are proposed (I _hate_ shared_ptr-like ref-counted stuff, in large projects they tend to cause much more trouble then they're worth, especially memory leaks due to shared_ptr loops are troublesome, causing both syntactic and semantic memory leaks, ouch!), and (b) how to formalize the use of those non-owning ('naked') pointers/references and how to prevent them from being dereferenced when they're pointing to already-deallocated memory locations (and saying "don't use naked pointers/refs, ever" is not really practical IMNSHO).