// illustrates difference between call-by-value and by-reference 
// Walter Savitch
// 10/3/00
#include <iostream>
using std::cout; using std::endl; using std::cin;

// one is call-by-value, two is call-by-reference 
void doStuff(int one, int &two);

int main(){

    int n1=1, n2=2;

    cout << "n1 before function call = " << n1 << endl;
    cout << "n2 before function call = " << n2 << endl;

    doStuff(n1, n2);

    cout << "n1 after function call = " << n1 << endl;
    cout << "n2 after function call = " << n2 << endl;

}

void doStuff(int one, int &two) {
    one  = 111;
    cout << "one in function call = " << one << endl;

    two = 222;
    cout << "two in function call = " << two << endl;
}