1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
|
/* File : example.h */
class Shape {
public:
Shape() {
nshapes++;
}
virtual ~Shape() {
nshapes--;
};
double x, y;
double *z;
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);
};
extern double do_op(Shape *s, double (Shape::*m)(void));
/* Functions that return member pointers */
extern double (Shape::*areapt())(void);
extern double (Shape::*perimeterpt())(void);
/* Global variables that are member pointers */
extern double (Shape::*areavar)(void);
extern double (Shape::*perimetervar)(void);
|
