C++ typeid()

Does anyone know how typeid() is implemented in C++???
I mean, how do I make a function like typeid() where I can pass the TYPE as a paramter.

Example:
int main()
{
    typeid(int);//<-- works of course
    f(int);//<-- how to do something like this
           //        without using macros or templates
}

>>55
Lisp is the highest level language of them all. It also has the most powerful macros. In fact once you've used Lisp macros you wonder how you ever got along with all that shitty #define crap.