如何使用C++编写一个简单的物流管理系统？

// User.h
class User {
private:
    std::string username;
    std::string passWord;
public:
    User(std::string username, std::string password);
    std::string getUsername();
    std::string getPassword();
};

// Item.h
class Item {
private:
    std::string itemName;
    double weight;
public:
    Item(std::string itemName, double weight);
    std::string getItemName();
    double getWeight();
};

// Order.h
class Order {
private:
    std::string orderNumber;
    User user;
    Item item;
public:
    Order(std::string orderNumber, User user, Item item);
    std::string getOrderNumber();
    User getUser();
    Item getItem();
};

// Logistics.h
class Logistics {
private:
    Order order;
    std::string status;
public:
    Logistics(Order order, std::string status);
    Order getOrder();
    std::string getStatus();
};

// System.h
class System {
private:
    std::vector<User> users;
    std::vector<Item> items;
    std::vector<Order> orders;
    std::vector<Logistics> logistics;
public:
    void addUser(User user);
    void deleteUser(User user);
    void updateUser(User user);
    void addOrder(Order order);
    void deleteOrder(Order order);
    void updateOrder(Order order);
    void addLogistics(Logistics logistics);
    void deleteLogistics(Logistics logistics);
    void updateLogistics(Logistics logistics);
    void login(std::string username, std::string password);
    // 其他功能函数...
};