复制在指针数组中动态创建的指针

Question

I am beginner,and i am facing problem when trying to copy one pointer to object in array of pointers..

 class Publication
 {
  char title[20];
  int idd;
public:

char* getT()
{
    return title;
}

virtual void getData()
{
    cout<<"Enter Title of Book";
    cin>>title;
    cout<<"Enter ID of Book";
    cin>>idd;
}
virtual void putData()
{

    cout<<"Title of Book : "<<title<<"\n";
    cout<<"ID of Book : "<<idd;
}
};

 class Book:private Publication
  {
    int pages;
  public:
    void getData()
    {
    cout<<"Enter Title of Book";
    cin>>getT();
    cout<<"Enter Pages ";
    cin>>pages;
    }
    void putData()
    {
        cout<<"Title of Book : "<<getT()<<"\n";
        cout<<"No of Pages : "<<pages;
    }
   };

Main Function

int main()
 {
  Publication *ptrpub[2];
  Book *ptr;

for(int i=0;i<2;i++)
{
    cout<<"Enter Data for Book Object";
    ptr=new Book; 
    ptr->getData();

Now within this loop, i want to move that pointer in an array of pointers to publication ie ptrpub[],where Book class inherits from Publication Privately

  ptrpub[i]=ptr;         //'Publication' is an inaccessible base of 'Book'

Is there any way to copy them,so i may use ptrpub[i]->putdata() to show all data entered for book object.. And I must keep that relationship between Book and Publication class.

Answer 1

The problem is that you inherit Book from Publication privately:

class Book:private Publication

This means that only Book 's implementation is aware that it inherits from Publication -- code external to the class does not know this, and so you cannot cast Book to Publication except from within members of Book (or friend members).

You can resolve this by inheriting publicly:

class Book:public Publication