物件102-2

#include <iostream>
using namespace std;

int num = 1;

class A{
public:
    A():id(num){
        name = id;
        num++;
        cout << "Constructor : Obj " << id << " of type A Name is " << name << endl;
    }
    ~A(){cout << "Destructor  : Obj " << id << " of type A Name is " << name << endl;}
    const int id;
    int name;
};

class B : public A{
public:
    B():id(num){
        name = id;
        num++;
        cout << "Constructor : Obj " << id << " of type B Name is " << name << endl;
    }
    ~B(){cout << "Destructor  : Obj " << id << " of type B Name is " << name << endl;}
    const int id;
    int name;
};


void swap1(A o1, B o2){
    A tmp = o1;
    o1.name = o2.name;
    o2.name = tmp.name;
}

void swap2(A &o1, B &o2){
    A tmp = o1;
    o1.name = o2.name;
    o2.name = tmp.name;
}


int main()
{
    A o1;
    B o2;
    swap1(o1, o2);

    {
        static A o3;
        swap2(o3, o2);
    }
}