// Ex5_07.cpp
  // Using a reference to modify caller arguments
  include <iostream>
  using std::cout;
  using std::endl;
  
  int incr10(int& num);                // Function prototype
  
  int main(void)
  {
     int num = 3;
     int value = 6;
  
     cout << endl
          << "incr10(num) = " << incr10(num);
  
     cout << endl
          << "num = " << num;
  
     cout << endl
          << "incr10(value) = " << incr10(value);
  
     cout << endl
          << "value = " << value;
  
     cout << endl;
     return 0;
  }
  
  // Function to increment a variable by 10
  int incr10(int& num)                 // Function with reference argument
  {
     cout << endl
          << "Value received = " << num;
  
     num += 10;                        // Increment the caller argument
                                       //  - confidently
     return num;                       // Return the incremented value
  }