Hi, I quoted a template class to put it into a mpl::vector doing this: boost::mpl::vectorstd::pair> Then, I obtained the 2nd element like this: using A=typename boost::mpl::at>::type; I need now to pass the original template class to a class like this: template class C> class B{ C _c; }; I'm tried using apply or bind, but couldn't figure out the way to make it in a way that B accept it as second parameter. I get errors of the kind: error: template argument for template template parameter must be a class template or type alias template I also posted the question in stack overflow so if someone participates in stack overflow and want some potints the question is: http://stackoverflow.com/q/24856504/861649?sem=2 Thanks in advance, Damian