单件类模板的继承实现

参考了网上一些资料，写了个单件类模板的继承实现。把单件定义为类模板，让所有需要实现单件的类都去继承这个单件类模板，从而保证每一个类只有一个实例。

 

 1 #include "stdafx.h"
 2 #include <iostream>
 3  using namespace std;
 4 /* 单件模板 */
 5 template<class T>
 6 class Singleton
 7 {
 8 public:
 9     static T* getInstance()
10     {
11         if (NULL == m_Instance )
12         {
13             m_Instance = new T;
14         }
15         return m_Instance;
16     }
17     static void releaseInstance()
18     {
19         if(NULL != m_Instance)
20             delete m_Instance;
21         m_Instance=NULL;
22         cout<<"memory released..."<<endl;
23     }
24 protected:
25     Singleton()
26     {
27         cout<<"singleton constructor..."<<endl;
28     }
29     virtual ~Singleton()
30     {
31         cout<<"singleton destructor..."<<endl;
32     }
33 
34 private:
35     Singleton(const Singleton& );
36     Singleton& operator= (const Singleton& );
37 
38 private:
39     static T* m_Instance;
40 };
41 template<class T>
42 T* Singleton<T>::m_Instance=NULL;
43 
44 
45 class App : public Singleton<App>
46 {
47 public:
48     friend class Singleton<App>;
49     void print() const
50     {
51         cout<<"hi,marrywindy"<<endl;
52     }
53 private:
54     App()
55     {
56         cout<<"app constructor..."<<endl;
57     }
58     ~App()
59     {
60         cout<<"app destructor..."<<endl;
61     }
62 private:
63     App(const App&);
64     App& operator= (const App& );
65 };
66 
67 
68 int _tmain(int argc, _TCHAR* argv[])
69 {
70     App::getInstance()->print();
71     App::releaseInstance();
72     return 0;
73 }
74 
75

欢迎大侠们指正....

posted on 2010-12-23 10:58  marrywindy  阅读(1361)  评论(0)  编辑  收藏  举报

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