__BITMAP_WORD
((__v)->_b[__BITMAP_WORD(__n, __v)] |= __BITMAP_BIT(__n, __v))
((__v)->_b[__BITMAP_WORD(__n, __v)] &= ~__BITMAP_BIT(__n, __v))
((__v)->_b[__BITMAP_WORD(__n, __v)] & __BITMAP_BIT(__n, __v))