Run Code According to Class type C++

I'm trying to run different codes according to what class the template T is passed as. I have 2 classes: Media and Customer. I have a template T and a function add(T type). What I want it to be able to do is effectively recognise which Class is being passed from T and add that type to an array as shown below.

template <typename T>

void add(T type){

    if(type = Customer) { // This is pseudo code of what I want it to do

        allCustomers.push_back(type);
        cout << "Added Successfully";

    }

    else if (type = Media){
        allMedia.push_back(type);
        cout << "Added Successfully";
    }

And this is how i'm trying to pass it:

l.add(new book("test","test")); 

I'm sorry if I didn't explain this better, but if anyone could help, that would be great! Thanks.