| /* File : example.h */ |
| #include <vector> |
| |
| class Shape { |
| public: |
| Shape() { |
| nshapes++; |
| } |
| virtual ~Shape() { |
| nshapes--; |
| } |
| double x, y; |
| void move(double dx, double dy); |
| virtual double area(void) = 0; |
| virtual double perimeter(void) = 0; |
| static int nshapes; |
| }; |
| |
| class Circle : public Shape { |
| private: |
| double radius; |
| public: |
| Circle(double r) : radius(r) { } |
| virtual double area(void); |
| virtual double perimeter(void); |
| }; |
| |
| class Square : public Shape { |
| private: |
| double width; |
| public: |
| Square(double w) : width(w) { } |
| virtual double area(void); |
| virtual double perimeter(void); |
| }; |
| |
| |
| Circle* createCircle(double w); // this method creates a new object |
| Square* createSquare(double w); // this method creates a new object |
| |
| class ShapeOwner { |
| private: |
| std::vector<Shape*> shapes; |
| ShapeOwner(const ShapeOwner&); // no copying |
| ShapeOwner& operator=(const ShapeOwner&); // no copying |
| public: |
| ShapeOwner(); |
| ~ShapeOwner(); |
| void add(Shape* ptr); // this method takes ownership of the object |
| Shape* get(int idx); // this pointer is still owned by the class (assessor) |
| Shape* remove(int idx); // this method returns memory which must be deleted |
| }; |
| |
| |