Question

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Undefined symbols “vtable for …” and “typeinfo for…”?
C++ Undefined Reference to vtable and inheritance

I’ve a problem with a little project required from my university.
It’s a simple project of a chess game.

I’ve the obscure error undefined reference to `vtable for XXX
when I define an inherited class from an abstract one…
This is the code

Pieces.h

class Pieces {
public:
   Pieces(char color) : pieceColor(color) {}
   virtual ~Pieces() {}
   virtual char getPieceType() = 0;
   char getColor() {
     return pieceColor;
   }

   virtual bool isLegalMove(int srcRow, int srcCol, int destRow, int destCol, Pieces* board[8][8]) = 0;

private:
   virtual bool areSquaresLegal(int srcRow, int srcCol, int destRow, int destCol, Pieces* board[8][8]) = 0;
   char pieceColor;
};

and this a sample inherited class i.e. the pawn one

Pawn.h

#include "Pieces.h"

class Pawn: public Pieces {
public:
    Pawn(char color) : Pieces(color) {}
    ~Pawn();
private:
    virtual char getPieceType() {
        return 'P';
    }
    bool areSquaresLegal(int srcRow, int srcCol, int destRow, int destCol, Pieces* board[8][8]);
    bool isLegalMove(int srcRow, int srcCol, int destRow, int destCol, Pieces* board[8][8]);
};

The last two methods are implemented in a .cpp file.
Every other class is similar to the pawn one obviously.

When I try to compile, the builder gives me: undefined reference tovtable for Pawn’`
with reference to the line where the constructor is:

Pawn(char color) : Pieces(color) {}

Where am I going wrong?

Answer 1

You say you’ve implemented the last two member functions. My guess is that you haven’t implemented the destructor that you’ve declared, but not defined in the class.

If you need a non-trivial destructor for the class, then make sure you implement it. If not, then remove its declaration.

In general, this error means that you’ve declared a non-pure virtual function and forgotten to implement it; some popular compilers place the class’s polymorphic metadata in the same translation unit as the first non-pure, non-inline member function, which in this case is the destructor. If you see the error for a class that’s supposed to be abstract, then it typically means that you’ve forgotten to declare some of its virtual functions pure.