In http://lists.boost.org/Archives/boost/2003/11/56289.php, there was a question on how one should locate all the mpl::pair's that match a given type when one was only interested in the first item in the pair. The suggested solution looked like something like this: #include <boost/mpl/vector.hpp> #include <boost/mpl/pair.hpp> #include <boost/mpl/find.hpp> #include <boost/mpl/transform_view.hpp> int main(int, char **) { using namespace boost; typedef mpl::vector< mpl::pair<int, int*>, mpl::pair<short, short*>, mpl::pair<long, long*>, mpl::pair<char, char*> > pairs; typedef mpl::find< mpl::transform_view< pairs, mpl::select1st<> >, long >::type::base iter; } However, mpl::select1st<> no longer is a part of boost and I don't see how to accomplish this despite having "C++ Template Metaprogramming" in my hands. I'd like to know what is the correct way in a recent version of boost, to accomplish this.