[Boost-users] [MPL] How to use a mpl::map

Hi, I'm new to MPL and I have difficulties to use the map container. I need to map (and then retrieve) some types based on they ID: I try the following code but it does not work.. sturct MSG_METHOD_CONNECT { .... } template<class MESSAGE> class PBMessage { public: PBMessage() {}; /* ... other methods ... */ private: MESSAGE m_Msg; }; // Map of types. The key is the Message opCode typedef typename mpl::map< mpl::pair >, mpl::pair >, > TMessageMap; // The Message type template < typename MessageMap, int opCode > typedef typename mpl::at::type::value TMessage; And to retrieve the type: TMessage msg; Could someone give me some suggestions? Regards, Daniele.