Does int * & has any real sense?

Question

I'm looking few exercise from university about C++ and I found out this exercise:

#include <iostream>
using namespace std;
int& f(int*&);
int& f(int*& x) {
    *x = 5;
    return *x;
}
int main() { 
    int y = 1, x; 
    int* z = &y; 
    x= f(z);
    cout << y << " " << x <<endl; 
}

I was wondering: does <any type>*& has any real sense? Isn't f(int*& x) the same as f(int x)? Aren't you passing the pointer to the L-value of the variable?

Answer 1

f(int*& x) is not the same as f(int x). In the first case x is a reference to an integer pointer whereas in the second case x is just an integer.

Lets start from the basics:

When you write f(int &x) means that x is a reference to an integer and you can change the value of x in the function and the change will be reflected in the calling function.

Similarly, when you write f(int*& x), it means that x is reference to an integer pointer and when you change the address that x points to, the change will also be reflected in the calling function.