In the code I'm giving you, there is E that derives from C, and I have a pointer to an object of C.
#include <iostream>
using namespace std;
class C {
public: virtual C* f(){ cout << "C::f()" << endl; return this; }
};
class E: public C {
public: E* f(){ cout << "E::f()" << endl; return this; }
};
int main(){
C* pc = new E;
auto p = pc->f();
cout << typeid(p).name() << endl;
}
When I call pc->f(), it goes to E::f() due to the virtual function, and I get it, but what is the return type of return this;?
Because this is a C*, but in the signature the method should return an E*.
If you run it, it prints:
E::f()
P1C
The type of p is C*, but the object it points to is an E.
If you print the typename of *p, you get (mangled) E.
cout << typeid(p).name() << endl << typeid(*p).name() << endl;
When you call f through an E*, you get an E* back.
int main(){
E* pe = new E;
C* pc = pe;
auto p1 = pe->f();
auto p2 = pc->f();
cout << typeid(E).name() << endl << typeid(C).name() << endl;
cout << typeid(p1).name() << endl << typeid(p2).name() << endl;
cout << typeid(*p1).name() << endl << typeid(*p2).name() << endl;
}