Problem with overloading operator+

Majid Kamali

Hello.
I wrote the code below:

 public static Point operator +(Point p1, Point p2)
        {
            return new Point(p1.X + p2.X, p1.Y + p2.Y);
        }

But Creates error below on "operator+" :
One of the parameters of a binary operator must be the containing type

What's the problem?

Thanks.

9 Replies

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Sam Hobbs16y ago
Accepted answer

"If operator function be one of its member functions, we don't need to inherit a class from it."

That is not the way that most object-oriented languages work. In C# you can create Extension methods; look at the documentation of those.
Majid Kamali16y ago
If operator function be one of its member functions, we don't need to inherit a class from it.
Kirtan Patel16y ago
if you dont inherit then how would you extend its functionality ?
Majid Kamali16y ago
for overloading an operator why should we inherit a class from it ?
Kirtan Patel16y ago
Point is a Struct Not Class you cannot inherit Struct .
Majid Kamali16y ago
I talk about predefined class Point.
I don't want to modify it's private members. I just want to create a new point and add new X and Y to it's members.
Kirtan Patel16y ago
which class you are talking about ?it depends upon the class weather it allow you take control of its private variable or not .
if it allows then you can inherit it and can overload operator in that derived class

Hope it helps you :)
Majid Kamali16y ago
Thanks.
But Can I overload an operator for a predefined class ?
If yes, Why it Creates Error ?
Kirtan Patel16y ago

do check "Do you like this answer" checkbox if it helps you :)

class CartsianPoint

    {

        private int x;

        private int y;

        public CartsianPoint()

        {

        }

        public CartsianPoint(int x, int y)

        {

            this.x = x;

            this.y = y;

        }

        public static CartsianPoint operator +(CartsianPoint p1,CartsianPoint p2)

        {

            CartsianPoint temp = new CartsianPoint(p1.X+p2.X,p1.Y+p2.Y);

            return temp;

        }



        public int X

        {

            get{return x;}

            set{x = value;}

        }

        public int Y

        {

            get { return y; }

            set { y = value; }

        }

    }

I used like below in Main Method

static void Main(string[] args)

        {

            CartsianPoint p1 = new CartsianPoint(10,10);

            CartsianPoint p2 = new CartsianPoint(20, 20);



            CartsianPoint result = p1 + p2;

            Console.WriteLine("p3 X:=" + result.X+" and p3 Y="+result.Y);

            Console.ReadKey();

        }