Need help understanding overload program

Hello,

I have a question regarding following code. It is overloading plus (+) operator.

Code:

---

#include <iostream>
using namespace std;
class CVector {
public:
int x,y;
CVector () {};
CVector (int,int);
CVector operator + (CVector);
};
CVector::CVector (int a, int b) {
x = a;
y = b;
}
CVector CVector::operator+ (CVector param) {
CVector temp;
temp.x = x + param.x;
temp.y = y + param.y;
return (temp);
}
int main () {
CVector a (3,1);
CVector b (1,2);
CVector c;
c = a + b;
cout << c.x << "," << c.y;
return 0;
}

---

Question: When function + is called, which object is traced to param is it a or b? and while executing this function, x = ?, y =?

Thanks for any help..

In that case, b would be param. You could even say:

Code:

---

c = a.operator+(b);

---

Indent any code you post!

Quote:

---

Originally Posted by OCcounty

Question: When function + is called, which object is traced to param is it a or b?

---

To split hairs, neither. A copy of b is (logically) passed to the function as the argument named "param". Although a compiler is allowed to eliminate the copy, it is not required to.

Instead of:

Code:

---

CVector operator + (CVector v);

---

Why not use:

Code:

---

CVector operator+(const CVector& v);

---

Now you have const reference to object, instead of copy.