【C++】派生类对象初始化基类的引用

//派生类对象初始化基类的引用
//引用是别名，但这个别名只能包含派生类对象中的由基类继承来的隐藏对象

#include <iostream>
using namespace std;
class B
{
public:
B()
{
cout<<"B"<<endl;
}
void fun()
{
cout<<"B::fun()"<<endl;
}
private:
int x;
};

class D : public B
{
public:
D()
{
cout<<"D"<<endl;
}
void fun()
{
cout<<"D::fun()"<<endl;
}
void show()
{
cout<<"D::show()"<<endl;
}
private:
int y;
};
void main()
{
D d;
B &p=d;
p.fun();
//	p.show();          //错误，派生类对象初始化基类的引用不能用于派生类
}
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