return by refrence

/******************************************************************************

                              Online C++ Compiler.
               Code, Compile, Run and Debug C++ program online.
Write your code in this editor and press "Run" button to compile and execute it.

*******************************************************************************/

#include <iostream>
using namespace std;

class MyInt{
    public:
        int my_int;
        MyInt():my_int(0){}
        MyInt(int i): my_int(i){}
};

MyInt& returnInt(MyInt& my_int){
    return my_int;
};

int& returnPureInt(int& my_int){
    ++my_int;
    return my_int;
};

int main()
{
    MyInt my_10 = MyInt(10);
    MyInt my_11 = returnInt(my_10);
    // MyInt& my_11 = my_10;
    my_11.my_int = 11;

    cout<<"Hello World "<<my_10.my_int<<" "<<my_11.my_int;

    // int pure_int = int(100);
    // int pure_int_2 = returnPureInt(pure_int);
    // ++pure_int_2;
    // cout <<"Hello world " << pure_int <<" "<<pure_int_2;
    return 0;
}