Sharing the same container between two different classes - c++

Question

Say for example I have the following two classes:
class ChessBoard
{
std::vector <ChessPiece> pieceList;
}
class ChessSquare
{
std::vector <ChessPiece> pieceList;
}
What I want to do is allow both classes to have access to the exact same ChessPiece vector, so that both of them have read/write access to the EXACT SAME ChessPiece data. So say for example when ChessSquare updates the pieceList vector, the corresponding pieceList vector in ChessBoard will get updated as well, and vice-versa. How would I go about implementing this?

Answer 1

Use a pointer. Give them each a copy of the same pointer to the vector.
If you give them each a std::shared_ptr you get the added benefit of reference counting and cleanup handled once neither of the classes are left using it.

Answer 2

Use pointer or reference to the pieceList.

Answer 3

Create object ChessPiece and send pointer of this object to ChessBoard and ChessSquare. I hope you access to ChessPiece only from one thread, instead you have to protect your ChessPiece using mutex or something like that.

Answer 4

Pointer is the obvious choice. BUT if you are feeling crazy and want to over-engineer your project you could encapsulate the vector within its own class and make that class a globally visible singleton

Answer 5

Use pointer maybe a good way, but i think you should achieve your point like this:
class ChessBase
{
static std::vector <ChessPiece> pieceList;
}
class ChessBoard : ChessBase
{
//to do what you want.
}
class ChessSquare : ChessBase
{
//to do what your want.
}
You can access the vector in each class as their member.

Answer 6

Seeing as a chessboard is composed of chess squares, I might suggest having the vector in the chessboard class and a reference to it in the chess square class, maybe like so:
typedef std::vector<ChessPiece> PIECES
class ChessBoard
{
public:
ChessBoard()
{
// NOTE! your app might have more squares than this:
m_pSquare = new ChessSquare( pieceList );
}
private:
PIECES pieceList;
ChessSquare* m_Square;
}
class ChessSquare
{
public:
ChessSquare( const PIECES& pieces )
: refPieceList(pieces)
{
}
private:
const PIECES& refPieceList;
}