sorry, I forgot to change the names of those classes. I am deeply sorry for my unconscious /***********CValue**********/ template< typename tvalue > class CValue { public: CValue( tvalue value ) : value_(value) {}; private: tvalue value_; }; /***********end of CValue*********/ /***********Type**************/ template<typename T, template <typename> class Value> struct Type { typedef boost::shared_ptr< Value<T> > pValue; }; /********end of Type************/ /**********Composition**********/ template<typename T> class Composition //digital image processing { public: Composition(); virtual ~Composition(); shared_ptr< T > createCValue(); }; template<typename T> Composition<T>::Composition() {} template<typename T> Composition<T>::~Composition() {} template<typename T> shared_ptr< T > Composition<T>::createCValue() { typename Type<T, CValue>::pValue c(new Composition< T >); return c; } /*********end of composition***********/ /**********main************/ int main() { Type<matrix<double>, Composition>::pValue C(new Composition<matrix<double>
); Type<matrix<double>, CValue>::pValue D; D = C->createCValue();
cout<<"system pause"<<endl; cin.get(); } /*********end of main********/ I hope I could create the instance of CValue through class Composition so I wrote a "createCvalue" function in the class Composition -- View this message in context: http://old.nabble.com/some-problems-about-shared_ptr-tp29674340p29682576.htm... Sent from the Boost - Users mailing list archive at Nabble.com.