Question about Templates and passing arguments

Hello all,
I am currently taking a Data Structures course and we are discussing the topic of templates and its remifications in the world of generic programming. I had a few questions if anyone would like to answer them.
I present to you the swap function as a generic algorithm:

Code:

---

template <typename T>
void swap (T& t1, &T t2)
{
    T temp;
    temp = t1;
    t1 = t2;
    t2 = temp;
}

---

My question is regarding the arguments for this template function. Why are they being passed in like this? Any advantages or disadvantages to this way of argument passing? Thank you.

I am assuming you are referring to passing a reference? The advantages are:

You can change the object, just as if you had passed a pointer.
You can use non-pointer syntax.
A reference will always be non-null.

Also, the biggest advantage at times is the the reference is usually quiker to pass than the whole object (like a pointer)

So if your object is 40bytes, its easier to pass a 4 byte reference