Singleton 创建

#include<stdio.h> #include<iostream> using std::cout; using std::endl; // 在内存中，通过该对象只能创建唯一的对象 // 1.该对象不能是栈对象 // 2.该对象 只能是堆对象 class Singleton{ public: static Singleton * GetInstance(){ if(NULL==_PInstance){ _PInstance =new Singleton; } return _PInstance; } void Print() { cout<<"Singleton created"<<endl; } private: Singleton(){ } private: static Singleton *_PInstance; }; Singleton * Singleton::_PInstance=NULL; int main() { Singleton *p1 = Singleton::GetInstance(); Singleton *p2 = Singleton::GetInstance(); p1->Print(); printf("p1=%p\n",p1); printf("p2=%p\n",p2); }