Friend Operator << overloading issues, - c++

Question

I'm having an issue with my operator<< overloading where I can not access the private variables of the class it is in no matter what I do because it will say that the variables are private as a compiler error. This is my current code:
#include "library.h"
#include "Book.h"
using namespace cs52;
Library::Library(){
myNumberOfBooksSeenSoFar=0;
}
//skipping most of the functions here for space
Library operator << ( ostream &out, const Library & l ){
int i=myNumberOfBooksSeenSoFar;
while(i<=0)
{
cout<< "Book ";
cout<<i;
cout<< "in library is:";
cout<< l.myBooks[i].getTitle();
cout<< ", ";
cout<< l.myBooks[i].getAuthor();
}
return (out);
}
And the function prototype and private variables in library.h are
#ifndef LIBRARY_H
#define LIBRARY_H
#define BookNotFound 1
#include "Book.h"
#include <iostream>
#include <cstdlib>
using namespace std;
namespace cs52{
class Library{
public:
Library();
void newBook( string title, string author );
void checkout( string title, string author ) {throw (BookNotFound);}
void returnBook( string title, string author ) {throw (BookNotFound);}
friend Library operator << ( Library& out, const Library & l );
private:
Book myBooks[ 20 ];
int myNumberOfBooksSeenSoFar;
};
}
#endif

Answer 1

Your << operator should have this protoype:
std::ostream& operator << ( std::ostream &out, const Library & l )
^^^^^^^^^^^^^
You need to return a reference to std::ostream object so that you can chain stream operations.
Also, If you declare it as friend in your Library class you should be able to access all the members(private/protected) of the Library class in your overloaded function.
As such i fail to understand your code, You declared your << operator as:
friend Library operator << ( Library& out, const Library & l );
^^^^^^^^^^^^
You defined your operator function with prototype:
Library operator << ( ostream &out, const Library & l )
^^^^^^^^^^^
They are different!
In short you never declared the function where you are accessing the private member as a friend of your class and Hence the error.
Also, the return type is Incorrect as I mentioned before.