... Turns out that the problem can be solved rather elegantly (for VC6.5, anyway :) The following code compiles in VC 6.5 : #pragma warning (disable:4786) #include <map> #include <list> template<typename A0,typename A1> void deduce_container(std::list<A0,A1>::iterator) { int b=0; } template<typename A0,typename A1,typename A2,typename A3,typename A4> void deduce_container(std::_Tree<A0, A1, A2, A3, A4>::iterator) { int b=0; } void main() { std::map<int,double>::iterator a; std::list<int*>::iterator b; deduce_container(a); deduce_container(b); } (Note that std::set<A0,A1,A2>::iterator is a typedef, and can not be deduced. std::_Tree<...>::iterator is an nested class, and can be deduced) I don't know if this is legal for other compilers, but if it is, we should define a new macro: REGISTER_NESTED_TEMPLATE_CLASS(std::list,2,iterator) It would then be possible to solve the stl problem outside the typeof library, in e.g. the stl/register.hpp (With separate registrations for the different stl-implementations, of course) Peder