Scott McMurray wrote

My apologies, I didn't know that. Certainly a very nice feature as it means that even without the virtual destructor both would be safe.

Promises to double-check the documentation before replying next time,

No worries. It wasn't exactly a highly advertised feature. Besides, the note implied that older versions of shared pointer didn't do that, so I just figured you learned about shared pointers before they added it. Andrew