C++ examples for Class:dynamic_cast
Tests dynamic casts
//RTTI must be enabled in compiler #include <iostream> #include <typeinfo> //for dynamic_cast using namespace std; class Base//from w w w . j a v a 2 s . com { protected: int ba; public: Base() : ba(0) { } Base(int b) : ba(b) { } virtual void vertFunc() //needed for dynamic_cast { } void show() { cout << "Base: ba=" << ba << endl; } }; class Derv : public Base { private: int da; public: Derv(int b, int d) : da(d) { ba = b; } void show() { cout << "Derv: ba=" << ba << ", da=" << da << endl; } }; int main() { Base* pBase = new Base(10); //pointer to Base Derv* pDerv = new Derv(21, 22); //pointer to Derv //derived-to-base: upcast -- points to Base subobject of Derv pBase = dynamic_cast<Base*>(pDerv); pBase->show(); //"Base: ba=21" pBase = new Derv(31, 32); //normal //base-to-derived: downcast -- (pBase must point to a Derv) pDerv = dynamic_cast<Derv*>(pBase); pDerv->show(); //"Derv: ba=31, da=32" return 0; }