1   // Fig. 7.3: fig07_03.cpp
2   // Attempting to initialize a constant of
3   // a built-in data type with an assignment.
4   #include <iostream.h>
5   
6   class Increment {
7   public:
8      Increment( int c = 0, int i = 1 );
9      void addIncrement() { count += increment; }
10     void print() const;
11  private:
12     int count;
13     const int increment;
14  };
15  
16  // Constructor for class Increment
17  Increment::Increment( int c, int i )
18  {             // Constant member 'increment' is not initialized
19     count = c;
20     increment = i;  // ERROR: Cannot modify a const object
21  }
22  
23  // Print the data
24  void Increment::print() const
25  {
26     cout << "count = " << count
27          << ", increment = " << increment << endl;
28  }
29  
30  int main()
31  {
32     Increment value( 10, 5 );
33  
34     cout << "Before incrementing: ";
35     value.print();
36  
37     for ( int j = 0; j < 3; j++ ) {
38        value.addIncrement();
39        cout << "After increment " << j << ": ";
40        value.print();
41     }
42  
43     return 0;
44  }