Template question

[Technocrat]

Is there a way to tell what type of VAR comes in through a template function?

like this for example

template <typename T>
void Combine(T &a, T &b)  
{
  if int or long
    a = a + b;
  if string
    a += b;
  if char
   strcpy(a,b);
  etc..
} 

I though I saw somewhere how to do this, but I can't find it.

Thanks