#include <iostream>
using namespace std;

class Two;
class One{
    int x;
public:  
    One(int a){x=a;}
    int Getx(){return x;}
    void func(Two&);
};

class Two{
    int y;
public:
    Two(int b){y=b;}
    int Gety(){return y;}
    friend void One::func(Two&);
};

void One::func(Two& r)
{r.y=x;}

void main(){
    One obj1(5);
    Two obj2(8);
    cout<<obj1.Getx()<<" "<<obj2.Gety()<<endl;
    obj1.func(obj2);
    cout<<obj1.Getx()<<" "<<obj2.Gety()<<endl;
}
输出结果是：5  8
            5  5
对于这个结果，5 8是可以理解的，可是没法理解5 5的输出结果。还是书没看透，哪位前辈可以帮我指点一下。谢谢！