Softwareentwicklung in C++ - ASC

268 10. Memory – ein kleines Beispiel
23 protected :
24
25 /∗ This v a r i a b l e holds the s i n g l e i n stance o f t h i s d e l e t o r .
26 ∗ To obtain t h i s instance , getInstance has to be c a l l e d
27 ∗/
28 static DontDelete d e l e t o r ;
29
30 /∗ This c l a s s i s implemented as a s i n g l e t o n , so the constructor
31 ∗ must not be public .
32 ∗/
33 DontDelete ( ) { }
34
35 /∗ This c l a s s i s implemented as a s i n g l e t o n , so the d e s t r u c t o r
36 ∗ must not be public .
37 ∗/
38 virtual ˜ DontDelete ( ) { }
39 public :
40
41 /∗ This method i s used to obtain an i n s t a n c e o f the d e l e t o r
42 ∗/
43 static DontDelete & getInstance ( )
44 {
45 return ( d e l e t o r ) ;
46 }
47
48 /∗ This i s the dummy c a l l b a c k implementation that does not
49 ∗ d e l e t e anything . . .
50 ∗ @param obj The pointer to the o b j e c t to be deleted
51 ∗/
52 virtual void deleteObject ( void ∗ obj ) {}
53
54 } ;
55
56
57 //−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−
58 /∗ A concrete d e l e t o r f o r char ∗ elements
59 ∗/
60
61 class CharDeletor : public ObjectDeletor
62 {
63 private :
64 /∗ Copy construction i s not allowed
65 ∗/
66 CharDeletor ( const CharDeletor& s r c ) {}
67 protected :
68
69 /∗ This v a r i a b l e holds the s i n g l e i n s t a n c e o f t h i s d e l e t o r .
70 ∗ To obtain t h i s instance , getInstance has to be c a l l e d
71 ∗/
72 static CharDeletor d e l e t o r ;
73
74 /∗ This c l a s s i s implemented as a s i n g l e t o n , so the constructor
75 ∗ must not be public .
76 ∗/
77 CharDeletor ( ) { }
78
79 /∗ This c l a s s i s implemented as a s i n g l e t o n , so the d e s t r u c t o r
80 ∗ must not be public .
81 ∗/
82 virtual ˜ CharDeletor ( ) { }
83 public :
84
85 /∗ This method i s used to obtain an i n stance o f the d e l e t o r
86 ∗/
87 static CharDeletor & getInstance ( )
88 {