#include <iostream>
using namespace std;
void increment(int *m){ // alias int *m = a; address pointed by m is the address pointed by a
  (*m)++;
  cout << " m is " << *m << "\n";
}

int main(){ 
  int *a = new int(0);
  cout << " a is " << *a << "\n"; // output: a is 0
  increment(a);                   // output: m is 1 
  cout << " a is " << *a << "\n"; // output: a is 1
  return 0; 
}