Unresolved externals [Constructors]

Question

Possible Duplicate:
What is an undefined reference/unresolved external symbol error and how do I fix it?

I have a problem with the Linker which I just can't solve.. Already tried anything I could think of I have a Baseclass (Person) and a Derived Class (Dealer) and I just want to call the Constructor from the CardStack Class which is a member in the Dealer class.

Here is my code:

Person.h

#ifndef PERSON_H
#define PERSON_H
#include "Card.h"
#include "Hand.h"

class Person
{
public:
    Person(void);
    virtual ~Person(void);
    virtual bool TakeCard(Card c);
    virtual bool Lost(void);

protected:
    virtual void CheckLost(void);
    bool b_Lost;
    Hand m_Hand;
};
#endif

Dealer.h

    #ifndef DEALER_H
#define DEALER_H

#include "Person.h"
#include "Card.h"
#include "CardStack.h"

class Dealer : public Person
{
public:
    Dealer(int stackcount);
    virtual ~Dealer(void);
    bool TakeCard(Card c);
    bool Lost(void);
    Card GiveCard(Card c);

protected:
    void CheckLost(void);
    CardStack m_GameStack;
};
#endif

Dealer.cpp

#include "Dealer.h"

Dealer::Dealer(int stackcount) : Person(), m_GameStack(stackcount)
{

};

Dealer::~Dealer(void)
{

};

bool Dealer::TakeCard(Card c)
{
    if(!b_Lost || m_Hand.GetTotal() <= 17)
    {
        m_Hand.Take(c);
        CheckLost();
        return true;
    }

    return false;
};

void Dealer::CheckLost()
{
    if (m_Hand.GetTotal() > 21)
    {
        b_Lost = true;
    }
};

bool Dealer::Lost()
{
    return b_Lost;
};

I honestly tried everthing I could think of but I couldn't figure out what the mistake is...

Here is the Output when compiling Dealer.cpp:

1>Dealer.obj : error LNK2019: unresolved external symbol "public: virtual __thiscall Person::~Person(void)" (??1Person@@UAE@XZ) referenced in function __unwindfunclet$??0Dealer@@QAE@H@Z$0

1>Dealer.obj : error LNK2001: unresolved external symbol "public: virtual bool __thiscall Person::TakeCard(class Card)" (?TakeCard@Person@@UAE_NVCard@@@Z)

1>Dealer.obj : error LNK2001: unresolved external symbol "public: virtual bool __thiscall Person::Lost(void)" (?Lost@Person@@UAE_NXZ)

1>Dealer.obj : error LNK2001: unresolved external symbol "protected: virtual void __thiscall Person::CheckLost(void)" (?CheckLost@Person@@MAEXXZ)

Answer 1

It looks like you are trying to compile Dealer.cpp into a program on its own. That doesn't work because it depends on the definition of the methods in Person, which are probably in Person.cpp. It would have been helpful if you had shown us the command you used to compile. But assuming you're using g++, what you probably tried to do is

g++ Dealer.cpp

What you should have done is either

g++ Person.cpp Dealer.cpp etc.

or

g++ -c Dealer.cpp
g++ -c Person.cpp

etc., and then

g++ Dealer.o Person.o etc.