Thread: Base and Derived Class Constructors with Different Signatures

Base class constructor:

Code:

Port(const char* brand = "none", const char* style = "none", int bottles = 0)

Derived class constructor:

Code:

VintagePort(const char* brand = "none", int bottles = 0, const char* nickname = "none", int year = 0)

Vintage is a style of port and hence style has been removed from the derived class, VintagePort, constructor.

I have written the derived class constructor as follows:

Code:

VintagePort::VintagePort(const char* brand, int bottles, const char* nickname, int year){
	Port::SetBrand(brand);
	Port::SetBottles(bottles);
	m_nickname = new char[strlen(nickname)+1];
	strcpy(m_nickname, nickname);
	m_year = year;
}

But I am not sure how to write the derived class copy constructor. Here is my unsuccessful attempt and any advice would be most welcome:

Code:

VintagePort::VintagePort(const VintagePort& vp){
	this->GetBrand()	=	new char [strlen(vp.Port::GetBrand())+1)]
}

FYI, the problem asks to use arrays to practice dynamic memory allocation.
PS:
The function names are self-explanatory; nevertheless for the sake of completeness, here is the full code so far:

Code:

#include<iostream>
#include<cstring>
using namespace std;
class Port{
	private:
		char* m_brand;
		char m_style[20];
		int m_bottles;
	public:
		Port(const char* brand = "none", const char* style = "none", int bottles = 0);
		Port(const Port& p); // copy constructor; 
		virtual ~Port(){delete[]m_brand;}
		Port& operator=(const Port& p);
		Port& operator+=(int b);// adds b to bottles; 
		Port& operator-=(int b);//subtracts b from bottles if available; 
		int BottleCount() const { return m_bottles;};
		void SetBrand(const char* brand = "none");
		char* GetBrand(){return m_brand;};
		void SetBottles(int bottles){m_bottles = bottles;};
		int GetBottles(){return m_bottles;};
		virtual void Show()const;
		friend ostream& operator<<(ostream& os, const Port& p);
};
class VintagePort: public Port{
	private:
		char* m_nickname;
		int m_year;
	public:
		VintagePort();
		VintagePort(const char* brand = "none", int bottles = 0, const char* nickname = "none", int year = 0);
		VintagePort(const VintagePort& vp);
		~VintagePort(){delete []m_nickname;};
		VintagePort& operator=(const VintagePort& vp);
		void Show()const{};
		friend ostream& operator<<(ostream& os, const VintagePort& vp);
};
int main(){}


Port::Port(const char* brand , const char* style , int bottles ){
	m_brand = new char[strlen(brand)+1];
	strcpy(m_brand, brand);
	strncpy(m_style, style, 19);
	m_style[19]='\0';
	m_bottles = bottles;
}
Port::Port(const Port& p){
	m_brand = new char[strlen(p.m_brand)+1];
	strcpy(m_brand, p.m_brand);
	strncpy(m_style, p.m_style, 19);
	m_style[19]='\0';
	m_bottles = p.m_bottles;
}
Port& Port::operator=(const Port& p){
	if(this ==&p){
		return *this;
	}
	delete m_brand;
	m_brand = new char[strlen(p.m_brand)+1];
	strcpy(m_brand, p.m_brand);
	for (int i = 0; i<20; i++){
		m_style[i]='\0';
	}
	strncpy(m_style, p.m_style, 19);
	m_style[19]='\0';
	m_bottles='\0';
	m_bottles = p.m_bottles;
	return *this;
}
Port& Port::operator+=(int b){
	m_bottles +=b;
}
Port& Port::operator-=(int b){
	if (m_bottles>=b){
		m_bottles -=b;
	} else
	m_bottles = 0;
}
void Port::Show()const{
cout<<"The brand is:"<<m_brand<<" of style:"<<m_style<<" and there are:"<<m_bottles<<" bottles in the collection"<<endl;
}
ostream& operator<<(ostream& os, const Port& p){
	os<<"The brand is:"<<p.m_brand<<" of style:"<<p.m_style<<" and there are:"<<p.m_bottles<<" bottles in the collection"<<endl;
	return os;
}
void Port::SetBrand(const char* brand){
	m_brand = new char[strlen(brand)+1];
	strcpy(m_brand, brand);
}
VintagePort::VintagePort(const char* brand, int bottles, const char* nickname, int year){
	Port::SetBrand(brand);
	Port::SetBottles(bottles);
	m_nickname = new char[strlen(nickname)+1];
	strcpy(m_nickname, nickname);
	m_year = year;
}
VintagePort::VintagePort(const VintagePort& vp){
	this->GetBrand()	=	new char [strlen(vp.Port::GetBrand())+1)]
}