Class data being corrupted after passing it through a paramater???

I've spent hours narrowing my problem down to these few lines of code.

This is how my two dimensional array of classes is defined:

Code:

square board[8][8];   //Creates a 8x8 array of square objects

This is the function I'm using to change the array's elements.

Code:

    void setBoard(square b[8][8])
    {
       int j;
       vector <CP> wPawn(8,'W'); //defines a vector of 8 CP objects
       vector <CP> bPawn(8,'B');
       for (j=0;j<8;j++)
       {
          b[j][1].place(&wPawn[j]);
          b[j][6].place(&bPawn[j]);   
       }
       cout << b[1][1];                //tests this individual square's data : Outputs correctly (the char 'P')
       pause();                            //similar to a system pause
    }

Where the strangeness comes in:

Code:

      setBoard(board);             //the function above   
       cout << board[1][1];       //tests this individual square's data : Outputs a seemingly random character ('=' O_o)
       pause();                          //similar to a system pause

When I output the whole array, the unchanged square objects output correctly. However, the ones that are changed inside of setBoard() become corrupted or something. Is there anything wrong with the way I'm passing that parameter? I've gotten away with doing it like this before.

I have to think that it has something to do with your vectors being destroyed once the function is finished.

> b[j][1].place(&wPawn[j]);
What's a square class do?

This looks suspiciously like saving a pointer to a local variable to me.

If you want to change the value of a variable in a function, you have to pass a pointer to that function or a reference in C++.

If you want to write a competent chess program, why use classes at all. Use bitboards, or 0x88 boards, or use classes to represent entire boards (this at least makes more sense to me). If you use piles of abstraction, your program would probably do no better than 8 ply using the best algorithms even on Deep Blue hardware, for instance. (If you're working on another senseless class assignment or not writing any AI at all, well you can ignore this at your own peril.)

system("pause") is doubleplusungood, use cin.get() while you have it.

Why not

Code:

enum piece_type
{
    empty, bpawn, wpawn, //etc
};

class board
{
    protected:
        piece_type board_data[8][8];
    public:
        //stuff...
}

I see what the problem is. Once the function is finished it deletes every local variable, including the vectors. I guess I was too tired to realize that last night.