Hi there, subject probably sounds a bit strange but here is what I'm trying to accomplish. The problem description goes like this: using namespace boost; using namespace boost::fusion; struct A; struct B; struct C; int main() { typedef vector< A, B, C > types; // how to translates typed into the following?? typedef vector< std::vector<A>, std::vector<B>, std::vector<C> > vector_of_types; return 0; } I'm looking for a generic approach to do this. To me it seems like it should be possible by taking parts of the MPL lib, like mpl::push_back, and parts of the fusion lib, like fusion::for_each. Any ideas? Thanks ahead, Christian