[C++知识库]c++primer plus第十三章4题Benevolent Order of Programmers用来维护瓶装葡萄酒酒箱

class Port
{
private:
	char*brand;
	char style[20];
	int bottles;
public:
	Port(const char*br = "none", int b = 0,const char *st = "none");
	Port(const Port&p);
	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;
	int year;
public:
	VintagePort();
	VintagePort(const char*br, int b, const char*nn, int y);
	VintagePort(const VintagePort &vp);
	~VintagePort(){ delete[]nickname; };
	VintagePort &operator=(const VintagePort &vp);//容易混淆，没有实际意义
	void Show()const;//虚函数在派生类重新定义
	friend ostream&operator<<(ostream &os, const VintagePort &vp);//友元函数不能为虚
};
Port::Port(const char*br,  int b,const char *st)
{
	brand = new char[strlen(br) + 1];
	strcpy(brand, br);
	strcpy_s(style, st);
	bottles = b;
}
Port::Port(const Port&p)
{
	brand = new char[strlen(p.brand) + 1];
	strcpy(brand, p.brand);
	strcpy_s(style, p.style);
	bottles = p.bottles;
}
Port&Port::operator = (const Port&p)
{
	if (this == &p)
	{
		return *this;
	}
	delete[]brand;
	brand = new char[strlen(p.brand) + 1];
	strcpy(brand, p.brand);
	strcpy_s(style, p.style);
	bottles = p.bottles;
}
Port&Port::operator += (int b)
{
	bottles += b;
	return *this ;
}
Port&Port::operator -= (int b)
{
	bottles -= b;
	return *this;
}
void Port::Show()const
{
	cout << "Brand:  " << brand << endl;
	cout << "Kind:    " << style << endl;
	cout << "Botle:   " << bottles << endl;
}
ostream &operator<<(ostream&os, const Port &p)
{
	os << p.brand << ",  " << p.style << ",   " << p.bottles << ",   \n";
	return os;
}
VintagePort::VintagePort() :Port()
{
	nickname = 0;
	year = 0;
}
VintagePort::VintagePort(const char*br, int b, const char*nn, int y) : Port(br, b)
{
	nickname = new char[strlen(nn) + 1];
	strcpy(nickname, nn);
	year = y;
}
VintagePort::VintagePort(const VintagePort &vp) :Port(vp)
{
	nickname = new char[strlen(vp.nickname) + 1];
	strcpy(nickname, vp.nickname);
	year = vp.year;
}
VintagePort &VintagePort::operator = (const VintagePort &vp)
{
	if (this == &vp)
	{
		return *this;
	}
	Port::operator=(vp);
	nickname = new char[strlen(vp.nickname) + 1];
	strcpy(nickname, vp.nickname);
	year = vp.year;
	return *this;
}
void VintagePort::Show()const
{
	Port::Show();
	cout << "nickname:  " << nickname << endl;
	cout << "year:   " << year << endl;
}
ostream&operator<<(ostream &os, const VintagePort &vp)
{
	operator<<(cout,(Port)vp);
	cout << ",   ";
	cout << vp.nickname << ",  " << vp.year << "\n";
	return os;
}