#include <cstdio> using namespace std; class BaseA{ public: virtual void foo()=0; }; class BaseB{ public: virtual void bar()=0; }; class Derived : public BaseA, public BaseB { public: void foo(){ printf("foo!\n"); } void bar(){ printf("bar!\n"); } }; int main() { Derived* derived=new Derived; BaseA* basea=derived; BaseB* baseb=derived; // 多继承导致basea和baseb不一样 printf("%p %p %p\n", (void*)derived, (void*)basea, (void*)baseb); return 0; }