Pointers and references in C++: what happens when b points to an alias of a

pointers_and_references_b_points_to_a.cpp

#include <iostream>
using namespace std;

void change_val(int &z);

int main() {
    int a = 1;
    int *b = &a;
    cout << "b points to an alias of the integer a\n";
    cout << "a=" << a << ", b=" << b << ", *b=" << *b << endl;
    // prints: a=1, b=0x7fffd3bf5de8, *b=1
    
    change_val(a);
    cout << "Function change_val gets an alias of a as input, ";
    cout << "and so changing the value of a inside the function, also changes a.\n";
    cout << "Furthermore, when a changes, so does the value that b points to:\n";
    cout << "a=" << a << ", b=" << b << ", *b=" << *b << endl;
    // prints: a=2, b=0x7fffd3bf5de8, *b=2
}

void change_val(int &z) {
    z++;
}