Copy constructors

• Consider:

      #include "point.h"
  
      void draw_segment( Point from, Point to ) { /* Connect two points */ }
  
      void main()
      {
          Point pt1( 5, 15 );
          Point pt2( 10, 20 );
          draw_segment( pt1, pt2 );
      }

• What should happen when objects are passed as parameters?

• Again, we want to be able to control semantics.

• If you don't provide a copy constructor, one will be provided for you,
  free of charge...

  • ...you guessed it.