类型兼容规则练习

类型兼容规则：共有派生类替代基类对象。赋值，引用，指针。

A1共有派B1，B1共有派生C1

#include <iostream>#include <iomanip>using namespace std;class A1{public: void display(int){cout <<"A1::display()"<<endl;}};class B1 :public A1{public:void display(){cout <<"B1::display()"<<endl;}};class C1:public B1{public:void display()const {cout <<"C1::display()"<<endl;}};main(){A1 a,*pa; B1 b,*pb; C1 c;b.display(); //调用成员函数b.A1::display(1); //调用从积累继承的成员函数 pa = &b; (*pa).display(1); // 兼容 c.display(); pb = &c; (*pb).display();}

输出：

B1::display()
A1::display()
A1::display()
C1::display()
B1::display()