#ifndef INVENTORY_H
#define INVENTORY_H

#include <iostream>
#include <list>

class Item {
 public:
  Item(int id = 0) : id(id) {}

  void operator= (const Item& other) {
    id = other.id;
  }

  int get_id() const { return id; }
  
  friend std::ostream& operator<< (std::ostream&, const Item&);
  
private:
  int id;   
};


typedef std::list<Item> ItemList;
typedef std::list<int> IdList;


class Inventory {
 public:
  // for a customer to place an order
  void order(int id);
  // received shipment of item id
  void shipped(int id);
  
 private:
  // list of items in stock
  ItemList in_stock;
  // list of id of items ordered
  IdList   ordered;
};


#endif // INVENTORY_H