C++只能允許類建立一個對象的做法

標籤：

方法一：利用引用計數：#include <iostream>using namespace  std;class  Object{public:        ~Object()    {        count=1;    }     Object()     {         if (count==0)         {             cout<<"該類只能建立一個對象！";             return ;         }         --count;             }private:    static int count;};int Object::count=1;int main(){      Object b;        return 0;}

方法二：利用友元函數#include <iostream>using namespace  std;class  Object{public:    ~Object(){}private:    Object(){}    Object(const Object&){}    Object& operator =(const Object &){}    friend Object& CreateObject()    {        static Object a;        return a;    }};int main(){      return 0;}
轉載自:http://blog.csdn.net/acdnjjjdjkdckjj/article/details/5621165

 

C++只能允許類建立一個對象的做法