Question

Is it possible to swap two variables without using ref/out keyword in C#(i.e. by using unsafe)?

for ex,

        swap(ref x,ref y);//It is possbile to by passing the reference

But, Is there any other way of doing the same thing. In the swap function you can use a temp variable. But, How to swap the variables without using ref/out keywords in C#?

Answer 1

A (very!) contrived example using delegates:

class Program
{
    static void FunkySwap<T>(T a, T b, Action<T> setA, Action<T> setB)
    {
        T tempA = a;
        setA(b);
        setB(tempA);
    }
    static void Main(string[] args)
    {
        string s1 = "big";
        string s2 = "apples";
        Console.WriteLine("BEFORE, s1: {0}, s2: {1}", s1, s2);
        FunkySwap(s1, s2, a => s1 = a, b => s2 = b);
        Console.WriteLine("AFTER,  s1: {0}, s2: {1}", s1, s2);
    }
}

While the above is pretty silly, using a delegate setter method can be useful in other situations; I’ve used the technique for implementing undo/redo of property modifications.