Hi, is it possible to return a shared_ptr to an interface from a dl?. I thought of the following what unfortunately doesn't work: // Interface.h - exe project class Interface { public: vitrtual void f( void ) = 0; virtual void g( void ) = 0; protected: ~Interface( void ) {} } typedef shared_ptr<Interface> InterfacePtr; InterfacePtr Create( void ) { // Load a special create function from the dll //.... return DLLCreate(); } // InterfaceImpl.h - dll project #include Interface class InterfaceImpl : public Interface { public: void f( void ) { /* ... */ }; void g( void ) { /* ... */ }; private: // No copy operations } extern "C" InterfacePtr DLLCreate( void ) { return InterfacePtr( new InterfaceImpl ); } At the moment this code doesn't compile because VS7.1 complains that it a function with extern "C" linkage can't return a shared_ptr<Interface> instance. How could I implement the desired behavior? Some other related questions regarding this topic: 1.) I link to the multithreaded C run-time dll - is this allowed? I read in an older post that only static CRT linking is allowed. 2.) Does the above code - loading the factory from the DLL as well and (hopefully) constructing the instance there - solve the boundary problems? I read some articles regarding this issue, but to be honest I haven't completly understood the problems that may occure in this case so far. Any help is greatly appreiciated.. -Dirk