//HeapOnly.cpp  只能在堆或者栈上分配内存的类  #include   <iostream>    using   namespace   std;       class   HeapOnly    {    public:    HeapOnly()   {   cout   <<   "constructor."   <<   endl;   }    void   destroy   ()   const   {   delete   this;   }    private:    ~HeapOnly()   {}      };       int   main()    {    HeapOnly   *p   =   new   HeapOnly;    p->destroy();    // HeapOnly   h;    // h.Output();       return   0;    }    //StackOnly.cpp    //2005.07.18------2009.06.05    #include   <iostream>    using   namespace   std;       class   StackOnly    {    public:    StackOnly()   {   cout   <<   "constructor."   <<   endl;   }    ~StackOnly()   {   cout   <<   "destructor."   <<   endl;   }    private:    void*   operator   new   (size_t);    };       int   main()    {    StackOnly   s;                                                             //okay    StackOnly   *p   =   new   StackOnly;                           //wrong       return   0;    }