编辑代码

#include <iostream>
using namespace std;
class Tst2 {
    int x;
    public:
    Tst2(int a){x=a;};
};
class Tst {
    public:
    const int & a;
    Tst(int const & x):a(x){};
};

int main() {

    Tst t1(2);
    cout << t1.a << endl; 
    cout << t1.a << endl;
    cout << "____________" << endl;
    int x(8);
    Tst2 t2(x);
    cout << t1.a << endl; 
    cout << t1.a << endl;




	
    
    
	return 0;
}