c++ - Type casting issues -

i hava code snippet below:

class classa { public:     virtual ~ classa() {};     virtual void functiona() {cout << "classa" << endl;} }; class classb { public:     virtual void functionb() {}; }; class classc : public classa, public classb { public:     void functiona(){cout << "why" << endl;}     void functionb(){cout << "class c funb" << endl;} };  classc aobject; classa* pa = &aobject; classb* pb = &aobject; classc* pc = &aobject;  int main() {     void* pvoid = static_cast<void *> (pb);     classa* pa2 = static_cast<classa*>(static_cast<classc*>(pb));      return 0; } 

is type-cast pvoid , pa2 right? or both of them wrong? (i tried compile it, have not got errors)

pvoid "right" in sense gives address of classb subobject of aobject untyped pointer. useful thing can cast classb*. note cast here redundant, since pointer can implicitly converted void*.

pa2 correctly initialised point classa subobject of aobject. since "cross-cast" (i.e. neither type derived other, both base classes of derived class), either need convert via derived type you've done, or use dynamic_cast if derived type not known @ compile time.