MOOC清华《面向对象程序设计》第4章：向上映射实验

#include <iostream>using namespace std;class Base{public:void print(){cout << "Base::print()" << endl;}};class Derive:public Base{public:void print(){cout << "Derive::print()" << endl;}};void fun(Base obj){obj.print();}int main(){Derive d;d.print();fun(d);return 0;}

第二行显示Base的原因是fun()函数的形参类型是Base。