class Single_Instance {public: Single_Instance * Get_Instance (); private: Single_Instance * pCur_Instance; int data; Single_Instance (); Single_Instance (Single_Instance & copy); ~ Single_Instance ();}; Single_Instance :: Single_Instance () {cout << "new SINGLE! "<< Endl;} SINGLE_INSTANCE :: SINGLE_INSTANCE :: SINGLE_INSTANCE (SINGLE_INSTANCE & COPY) {cout <<" new single by copy! "<< Endl;} single_instance :: ~ Single_instance () {cout <<" destroy single! <