s_class
return s != NULL && bitnset(bitidx(cl), s->s_class);
if (bitnset(bitidx(id), s->s_class))
setbitn(bitidx(class), s->s_class);
len = sizeof(s->s_class);
bitnset(bitidx(class), s->s_class) &&
bitnset(src, s->s_class))
setbitn(dst, s->s_class);
long *lp = (long *) s->s_class;