Pointers as arguments in functions

[chiara]

Hi all,

I am still pretty confused about pointers. Say that your function accepts the following variables:

function_(shared_ptr<Pink>& pi, shared_ptr<Red>& re, Cars* shape, Animals* ncb)

Now, do not care about the names you see. It is just an example. My questions is: why in some cases we choose the pointer using the asterisk and in other cases we choose the reference? What would be the reason behind it?

Thanks in advance for you explanations.

Chiara

[helios]

Other than syntax, the main difference between pointers and references is that references cannot be left unassigned. A function that takes a reference doesn't need to check that that reference is pointing to something, unlike with pointers.

void f(T *p,T &r){
    if (!p)
        return;
    //r can't be null
}

[PanGalactic]

In the case you cite, you are passing smart pointer objects by reference and raw pointers as, well, pointers. Smart pointers are not pointers. Rather they are objects with a pointer-like interface that are used to manage the life cycle of heap-allocated objects.