c++単例

内:

#include <iostream>



class Singleton

{

public:

    static Singleton *GetInstance()

    {

        return m_pSingletom;

    }

    

    int function() {

        return 0;

    }

private:

    static Singleton *m_pSingletom;

    //       

    Singleton()

    {

        if (m_pSingletom == NULL) {

            m_pSingletom = new Singleton();

        }

    }

};



Singleton *Singleton::m_pSingletom = 0;



int main(int argc, const char * argv[])

{

    Singleton *single = Singleton::GetInstance();

    int n = single->function();

    

    printf("%d
",n);

    std::cout << "Hello, World!
";

    return 0;

}

外

.h



#ifndef __SingletonDemo__Test__

#define __SingletonDemo__Test__



#include <iostream>



class Singleton

{

public:

    static Singleton *GetInstance();

    int function();

private:

    static Singleton *m_pSingleton;

};



#endif /* defined(__SingletonDemo__Test__) */

.cpp



#include "Test.h"



Singleton *Singleton::m_pSingleton = NULL;



Singleton *Singleton::GetInstance(){

    if (Singleton::m_pSingleton == NULL) {

        Singleton::m_pSingleton = new Singleton();

    }

    

    return m_pSingleton;

}



int Singleton::function()

{

    return 9;

}