I am using the ptr_container library (the version in the CVS) in my current project recently. I am really suprised by the strange behaviour of nullable ptr containers. If someone is using nullable ptr containers, there always are needs to construct a ptr container with specific size and filled in with all null pointers. However, I found that the ptr container can only "reserve" specfic sized buffered, but cannot be constructed with specific size: ptr_vector<nullable<int> > v(10); Instead, I have to write this: ptr_vector<nullable<int> > v(10); for (int i = 0; i < 10; i++) v.push_back(0); It is really a superise in my opinion, and write a loop (or use an STL algorithm) to fill the container manually is awkward and unnecessary. I think it is more intuitive and natural that the above constructor constructs a ptr_vector of size 10, with 10 null pointers inside. If the container is not nullable, it could default-construct 10 objects (or clone 10 from a given one) instead. Another superise is it seems that the iterator returned by associative ptr containers are not std::pair like STL containers do, but the values in the associative container. I cannot see the reason for this incompatibility with STL, nor can I find any documentation or examples on this. Am I missing something? Comments are welcome. Best regards, Yao, Zhen