When doing Function Pointers what is the purpose of using the address-of operator vs not using it?

Question

For the following code snippets why would I use one assignment vs another? thx

void  addOne(int &x)
{
    x +=1;
}

void (*inc)(int &x) = addOne;           


        

Answer 1

A function is already a pointer; therefore, you do not need the address operator.