C++:

Create a class called ReferenceManager that will be used as a container to hold objects of classes Article, Book, and TextBook.

1. ReferenceManager has a fixed capacity. It uses a fixed size array to store References.
2. The first reference added to the container will be added at position zero, the second one at position 1, and so on. A reference is always added at the next available position;
3. A ReferenceManager has one regular constructor: ReferenceManager(int capacity). The constructor must create an array of size capacity, which will be used to store References. It will also initialize the instance variables that your implementation requires.
4. ReferenceManager will have size data member, which will track the number of references in the array.
5. bool add(Reference & reference): adds a reference at the next available position and returns true, or returns false if the reference manager is full.
6. int get(int pos): returns the identifier of the Reference object stored at position pos of the ReferenceManager. You can assume that pos is a valid index, i.e. 0 <= pos < size;
7. bool delete(int pos): removes the element at position pos of this ReferenceManager and returns true, or returns false if pos was not a valid index. It must also shift the elements of the array towards the beginning of the array;
8. bool search(int id); return true if the reference with identifier id exists, false otherwise