Que renvoie le code suivant ?
class A {
public:
virtual void hello() {cout << "A" << endl;}
};
class B : public A {
public:
void hello() {cout << "B" << endl;}
};
void meet_value(A a1, A a2) {
a1.hello();
a2.hello();
}
void meet_reference(A& a1, A& a2) {
a1.hello();
a2.hello();
}
int main() {
B b;
A a;
meet_value(a, b);
meet_reference(a, b);
return 0;
}