#include <iostream>
using namespace std;

// stop pointer does not modify its contents
void increment_all (int* start, const int* stop) {
  while (start != stop) {
    ++(*start);  // increment value pointed
    ++start;     // increment pointer
  }
}

// start & stop pointers do not modify their contents
void print_all (const int* start, const int* stop)
{
  while (start != stop) {
    cout << *start << endl;
    ++start;     // increment pointer
  }
}

int main ()
{
  int numbers[] = {10,20,30};
  increment_all (numbers,numbers+3);
  print_all (numbers,numbers+3);
  return 0;
}