Make a const board temporarily modifiable. More...

#include <GoModBoard.h>

Public Member Functions
	GoModBoard (const GoBoard &bd, bool locked=false)
	Constructor.
	~GoModBoard ()
	Destructor.
GoBoard &	Board () const
	Explicit conversion to non-const reference.
	operator GoBoard & () const
	Automatic conversion to non-const reference.
void	Unlock ()
	Explicitely unlock the board.
void	Lock ()
	Explicitely lock the board.
Private Attributes
bool	m_locked
GoBoard &	m_bd
GoAssertBoardRestored	m_assertRestored

Detailed Description

Make a const board temporarily modifiable.

Allows functions to use a const board for performing temporary operations on the board (e.g. searches), as long as the board is in the same state after the function is finished. This class facilitates const-correctness and encapsulation, because it allows the owner of a board, which is the only one who is allowed to do persistent changes on the board, to hand out only a const reference to other code. The other code can still use the board for temporary operations without needing a copy of the board. GoModBoard does a const_cast from the const reference to a non-const reference in its constructor and checks with GoAssertBoardRestored in its destructor that the board is returned in the same state.

Example:

    // myFunction is not supposed to do persistent changes on the board
    // and therefore gets a const-reference. However it wants to use
    // the board temporarily
    void myFunction(const GoBoard& constBoard)
    {
        GoModBoard modBoard(constBoard);
        GoBoard& bd = modBoard.Board(); // get a nonconst-reference

        // ... play some moves and undo them

        // end of lifetime for modBoard, GoAssertBoardRestored is
        // automatically called in the destructor of modBoard
    }

There are also functions that allow to lock and unlock the board explicitly, for cases in which the period of temporary modifications cannot be mapped to the lifetime of a GoModBoard instance (e.g. because the period starts end ends in different functions).

Definition at line 45 of file GoModBoard.h.