Hi. I dont see why ptr_map throws in operator[], I think it should have the same behavior of std::map and return a default constructed object in case it doesnt find the key. Anyway, it is just a opinion. Im using ptr_map in production code and Im obligated to use find to see if the key is already in the map, if it isnt. create one. -- Felipe Magno de Almeida UIN: 2113442 email: felipe.almeida at ic unicamp br, felipe.m.almeida at gmail com, felipe at synergy com I am a C, modern C++, MFC, ODBC, Windows Services, MAPI developer from synergy, and Computer Science student from State University of Campinas(UNICAMP). To know more about: Unicamp: http://www.ic.unicamp.br Synergy: http://www.synergy.com.br current work: http://www.mintercept.com