Undefined reference to vtable for Compte - c++

Question

I'm trying to build a C++ project for a course I'm following and I'm having a lot of troubles.
I have this header:
#ifndef COMPTE_H_
#define COMPTE_H_
#include <string>
class Compte {
public:
Compte (unsigned int p_noCompte, double p_tauxInteret, double p_solde,const std::string& p_description);
virtual ~Compte (){} ;
void asgSolde (const double p_solde);
unsigned int reqNoCompte () const;
double reqTauxInteret () const;
double reqSolde () const;
std::string reqDescription () const;
std::string reqCompteFormate() const;
virtual Compte* clone() const;
virtual const double calculerInteret();
private:
unsigned int m_noCompte;
double m_tauxInteret;
double m_solde;
std::string m_description;
};
#endif /* COMPTE_H_ */
And the corresponding cpp file:
#include "Compte.h"
#include <string>
#include <sstream>
using namespace std;
Compte::Compte (unsigned int p_noCompte, double p_tauxInteret, double p_solde, const string& p_description)
: m_noCompte(p_noCompte), m_tauxInteret(p_tauxInteret), m_solde(p_solde), m_description(p_description)
{
}
void Compte::asgSolde (const double p_solde)
{
m_solde = p_solde;
}
unsigned int Compte::reqNoCompte () const{
return m_noCompte;
}
double Compte::reqTauxInteret() const{
return m_tauxInteret;
}
double Compte::reqSolde() const{
return m_solde;
}
string Compte::reqDescription() const{
return m_description;
}
string Compte::reqCompteFormate()const
{
ostringstream compteFormate;
return compteFormate.str();
}
However I have the following errors popping:
Description Resource Path Location Type
undefined reference to « vtable for Compte » Compte.cpp /Travail Pratique 2 line 14 C/C++ Problem
For the constructor in the .cpp file,
Description Resource Path Location Type
undefined reference to « vtable for Compte » Compte.cpp /Travail Pratique 2 line 14 C/C++ Problem
For the class Compte{ line in the .header file, and lastly
Description Resource Path Location Type
undefined reference to « vtable for Compte » Compte.h /Travail Pratique 2 line 16 C/C++ Problem
For the virtual ~Compte(){}; line.
What's wrong with my code, how can I correct this?

Answer 1

You forgot to implement 2 virtual methods, the clone and the calculerInteret.
That is why your linker is complaining. Your linker is not complaining about the destructor but he has trouble creating the virtual method table because 2 methods that are marked virtual, are missing.
Only a linker can find issues like that because in theory these methods can even be spread over multiple source files.
If it is your intent to create abstract methods do this :
virtual Compte* clone() const=0;
virtual const double calculerInteret()=0;
of course you realise you cannot instantiate classes that have abstract methods right ?

Answer 2

Not the problem in this case but may be the problem for anyone viewing this post:
Forgetting a body on a virtual destructor generates the following:
undefined reference to `vtable for CYourClass'.
I am adding a note because the error message is deceptive. (This was with gcc version 4.6.3.)
So add:
Compte::~Compte()
{
}
To your cpp file.
EDIT 1: As pointed out by Philip Stuyck: If the destructor were missing , then you would have had a similar error, but you can have it for any missing virtual method. If the virtual is inline yes or no does not matter, you just need one if its virtual.