C++ Singleton

File：singleton.hpp

1 #ifndef __SINGLETON_HPP_
 2 #define __SINGLETON_HPP_
 3 
 4 template <class T>
 5 class Singleton
 6 {
 7 public:
 8   static T* Instance() {
 9       if(!m_pInstance) m_pInstance = new T;
10       assert(m_pInstance !=NULL);
11       return m_pInstance;
12   }
13 protected:
14   Singleton();
15   ~Singleton();
16 private:
17   Singleton(Singleton const&);
18   Singleton& operator=(Singleton const&);
19   static T* m_pInstance;
20 };
21 
22 template <class T> T* Singleton<T>::m_pInstance=NULL;
23 
24 #endif

Usage：

1 #include "singleton.hpp"
 2 
 3 class Logger
 4 {
 5 public:
 6    Logger() {};
 7    ~Logger() {};
 8    bool openLogFile(string);
 9    void writeToLogFile(string);
10    bool closeLogFile(string);
11 private:
12    ...
13    ...
14 };
15 
16 bool Logger::openLogFile(std::string)
17 {
18    ...
19    ...
20 }
21 
22 ...
23 ...
24 
25 typedef Singleton<Logger> LoggerSingleton;   // Global declaration
26 
27 main()
28 {
29     ...
30 
31     LoggerSingleton::Instance()->openLogFile("logFile.txt");
32 
33     ...
34 }

来自：http://www.yolinux.com/TUTORIALS/C++Singleton.html

原文链接: https://www.cnblogs.com/good90/archive/2012/08/24/2654113.html

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