circular dependence problem?

[RPGillespie]

I'm having a frustrating time trying to get this to work:
I have 4 Classes: A, B, X, Y.

class A
{
...
   vector< vector <B> > chessboard;
}

class X;
class B
{
...
   X * ptr;
}

class B;
class X
{
public:
   X(vector< vector <B> > * board) : chessboard(board)
   virtual void doSomething() = 0;

protected:
   vector< vector <B> > * chessboard;
}

class Y : public X
{
public:
   Y(vector< vector <B> > * board) : X(board)
   void doSomething();
}

If I do this, no problem:

//code in class A
chessboard[0][0].setPiece(new Y(&chessboard));
cout << (chessboard[0][0].getX())->doSomething()

If I add this though:

//code in class Y, doSomething()
(*chessboard)[0][0].doSomethingElse();

The compiler explodes:

error: invalid use of incomplete type ‘struct B’
model/inc/X.h:13:7: error: forward declaration of ‘struct B’



All I want is for A and Y to be able to see and access the same chessboard! But the problem is that the board is a vector array of type B and B contains a pointer to X, which is the parent of Y. What am I missing?

[Peter87]

Put the member function definitions in source files and include the headers that is needed in them.

[RPGillespie]

Ok, I should clarify:

Classes A, B, X, and Y, are all defined in A.h, B.h, X.h, and Y.h

All of the code for the functions is defined in A.cpp, B.cpp, etc.

[Peter87]

ok sounds good. specify the base class constructor when you define the constructor and not in the declaration. You have done this for both X and Y constructor.

[bluecoder]

class X;
class B
{
...
   X * ptr;
}

And

class B;
class X
{
public:
   X(vector< vector <B> > * board) : chessboard(board)
   virtual void doSomething() = 0;

protected:
   vector< vector <B> > * chessboard;
}

cannot be declared in two ways in declared before one another .