/*
 * It's worth noting that reference variables must be initialized when they are
 * declared. Further, once you initialize a reference variable, you can't
 * change which variable it refers to.
 * 
 * Some examples that won't compile:
 *   int &ref_i; // BAD - can't declare reference type without initialization
 *   int &x = 5; // BAD - reference variables have to refer to other variables!
 *    
 *   int z;
 *   double &ref_to_z = z; // BAD - types don't match
 * 
 * The below shows an example that works
 */
void reference_variable_examples(){
      int x = 5;
      int y = 6;

      int &ref_x = x;  //declare a reference to x
      int &ref_y = y;  //declare a reference to y

      ref_x = ref_y;   // update the value of ref_x (and so the value of x)
                       // to be the value of ref_y (which is the value of y)

      std::cout << x << std::endl;     // prints 6

      ref_y = 7;                       // updates the value of ref_y (and y)

      std::cout << y << std::endl;     // prints 7

      std::cout << x << std::endl;     // prints 6

      x = 8;

      std::cout << ref_x << std::endl; //prints 8
};



/*
 * Now we will have an example of a function that uses a reference parameter
 *   note that x is not returned, you would expect x to not be impacted
 *   after this function, but the reference parameter changes that.
 *   
 */
void function_ref_params(int &x) 
{
      std::cout << "&x = " << &x << endl;
      x++;
}

/* This function calls the one above */
void call_ref_funct()
{
      x = 1;
      std::cout << "x = " << x << endl;
      std::cout << "&x = " << &x << endl;

      function_ref_params(x);
      std::cout << x << endl;
}