#include <iostream>
#include <cstdlib>
using namespace std;

void f(int i, int& r, int *p);

int main()
{
	int a {10};
	int b {20};
	int c {30};

	//Obvious that the function could change the value of c,
	//but dangerously not obvious that the fuction could also change
	//the value of b.
	f(a, b, &c);

	cout << "a == " << a << "\n"
		<< "b == " << b << "\n"
		<< "c == " << c << "\n";

	return EXIT_SUCCESS;
}

void f(int i, int& r, int *p)
{
	++i;   //Increments i, but this has no effect on the value of a.
	++r;   //increments b.
	++*p;  //Increments c.

	cout << "i == " << i << "\n"
		<< "r == " << r << "\n"      //Output the value of b.
		<< "*p == " << *p << "\n\n"; //Output the value of c.
}