Internally, the ptr_container classes use a void* container to do its magic. For example, ptr_vector uses a std::vector (and similarly for ptr_map and ptr_set) Or come to think of it, I believe it's actually vector and map, respectively. I'm curious as to why? This, of course, works just fine and since it's an internal detail it doesn't really matter. I'm just curious as to why you didn't use the more obvious (and perhaps wrong) choice of vector. Note: I'm not suggesting that it be changed. Functionally I have no issues with it, naturally, as it works. But, it does make debugging a little more interesting. But, even that is easy to get around. Just curious, -- Bill --