class Port
{
    private:
        char *brand;
        char style[20];     // i.e. tawny, ruby, vintage
        int bottles;
    public:
        Port(const char *br = "none", const char *st = "none", int b = 0);
        Port(const Port &p);            // copy constructor
        virtual ~Port() { delete [] brand;}
        Port & operator=(const Port &p);
        Port & operator+=(int b);
        Port & operator-=(int b);
        int BottleCount() const {return bottles;}
        virtual void Show() const;
        friend ostream &operator<<(ostream &os, const Port &p);
};
 
class VintagePort : public Port
{
    private:
        char * nickname;            // i.e. The Noble, or Old Velvet, etc.
        int year;                   // vintage year
    public:
        VintagePort();
        VintagePort(const char *br, int b, const char *nn, int y);
        VintagePort(const VintagePort &vp);
        ~VintagePort() {delete [] nickname;}
        void Show() const;
        friend ostream & operator<<(ostream &os, const VintagePort & vp);
};

Port(const char *br = "none", const char *st = "none", int b = 0);
VintagePort(const char *br, int b, const char *nn, int y);