C++单例模型的例子

#include <iostream>#include <new>using namespace std;class CGlobalInstance{  private:       CGlobalInstance();       virtual ~CGlobalInstance();       static CGlobalInstance* m_this;  public:     static CGlobalInstance* get_instance();   void out();};CGlobalInstance::CGlobalInstance(){}CGlobalInstance::~CGlobalInstance(){}void CGlobalInstance::out(){    cout<<"hi man"<<endl;}CGlobalInstance* CGlobalInstance::get_instance(){   if (NULL == m_this)   {     m_this = new CGlobalInstance();   }   return m_this;}CGlobalInstance* CGlobalInstance::m_this = NULL;int main(void){  CGlobalInstance::get_instance()->out();}