Hello, I have some slightly different code, which is presented in C++ Template Metaprogramming book to use the mpl::for_each function: mpl::for_each< mpl::transform<seq, wrap<_1> >::type >(dispatcher_type()); The deviation from the book is that my seq it not mpl::vector<...>, but mpl::map<...> In the docs is written, that mpl::transform operates on Forward Sequence. In the doc of forward sequence is stated that mpl::map is a model of it. Unfortunately this code does not compile. I could transform the map to vector, but I would not like doing it, since that would cost compile time and slow down the compilation. Is it a known issue or should not I expect map to work with transform? I also tried using itertors on seq, but that did not help. With Kind Regards, Ovanes Markarian