template<class LOCK_TYPE,class T, class CONTAINER>
inline void
Cell::Visit(const CellLock<LOCK_TYPE> &l, TypeContainerVisitor<T, CONTAINER> &visitor, Map &m) const
{
    const CellPair &standing_cell = l.i_cellPair;
    if (standing_cell.x_coord >= TOTAL_NUMBER_OF_CELLS_PER_MAP || standing_cell.y_coord >= TOTAL_NUMBER_OF_CELLS_PER_MAP)
        return;

    uint16 district = (District)this->data.Part.reserved;
    if(district == CENTER_DISTRICT)
    {
        m.Visit(l, visitor);
        return;
    }

    // set up the cell range based on the district
    // the overloaded operators handle range checking
    CellPair begin_cell = standing_cell;
    CellPair end_cell = standing_cell;

    switch( (District)this->data.Part.reserved )
    {
        case ALL_DISTRICT:
        {
            begin_cell << 1; begin_cell -= 1;               // upper left
            end_cell >> 1; end_cell += 1;                   // lower right
            break;
        }
        case UPPER_LEFT_DISTRICT:
        {
            begin_cell << 1; begin_cell -= 1;               // upper left
            break;
        }
        case UPPER_RIGHT_DISTRICT:
        {
            begin_cell -= 1;                                // up
            end_cell >> 1;                                  // right
            break;
        }
        case LOWER_LEFT_DISTRICT:
        {
            begin_cell << 1;                                // left
            end_cell += 1;                                  // down
            break;
        }
        case LOWER_RIGHT_DISTRICT:
        {
            end_cell >> 1; end_cell += 1;                   // lower right
            break;
        }
        case LEFT_DISTRICT:
        {
            begin_cell -= 1;                                // up
            end_cell >> 1; end_cell += 1;                   // lower right
            break;
        }
        case RIGHT_DISTRICT:
        {
            begin_cell << 1; begin_cell -= 1;               // upper left
            end_cell += 1;                                  // down
            break;
        }
        case UPPER_DISTRICT:
        {
            begin_cell << 1; begin_cell -= 1;               // upper left
            end_cell >> 1;                                  // right
            break;
        }
        case LOWER_DISTRICT:
        {
            begin_cell << 1;                                // left
            end_cell >> 1; end_cell += 1;                   // lower right
            break;
        }
        default:
        {
            assert( false );
            break;
        }
    }

    // loop the cell range
    for(uint32 x = begin_cell.x_coord; x <= end_cell.x_coord; x++)
    {
        for(uint32 y = begin_cell.y_coord; y <= end_cell.y_coord; y++)
        {
            Cell r_zone(CellPair(x,y));
            r_zone.data.Part.nocreate = l->data.Part.nocreate;
            CellLock<LOCK_TYPE> lock(r_zone, CellPair(x,y));
            m.Visit(lock, visitor);
        }
    }
}