state_element_t
statefd->element_size = sizeof (state_element_t) +
*flag = (((state_element_t *)((void *)ptr))->flags &
ptr += sizeof (state_element_t);
((state_element_t *)x - 1)->flags |= STATE_ELEMENT_IN_USE;
((state_element_t *)x - 1)->flags &= ~STATE_ELEMENT_IN_USE;