#include
using namespace std;
class base1{
public:
virtual void display() const;
};
void base1::display() const{
cout<<"base1::display()"<<endl;
}
class base2:public base1{
public:
void display() const;
};
void base2::display() const{
cout<<"base2::dispaly()"<<endl;
}
class driver:public base2{
public:
int display() const; //这边为什么会报错?
};
int driver::display() const{
cout<<"driver::display()"<<endl;
return 0;
}
void fun(base1* ptr){
ptr->display();
}
int main(){
base1 base1;
base2 base2;
driver driver;
fun(&base1);
fun(&base2);
fun(&driver);
return 0;
}