C#: Good/best implementation of Swap method

Question

I read this post about card shuffling and in many shuffling and sorting algorithms you need to swap two items in a list or array. But what does a good and efficient Swap met

Answer 1

Use:

void swap(int &a, int &b)
{
    // &a != &b
    // a == b OK
    a ^= b;
    b ^= a;
    a ^= b;
    return;
}

I did not realize I was in the C# section. This is C++ code, but it should have the same basic idea. I believe ^ is XOR in C# as well. It looks like instead of & you may need "ref"(?). I am not sure.