// the drain is complete and the Drain destructor is run.
self.head = drain_tail;
+ // `deque` and `ring` overlap in what they point to, so we must make sure
+ // that `ring` is "derived-from" `deque`, or else even just creating ring
+ // from `self` already invalidates `deque`.
+ let deque = NonNull::from(&mut *self);
+
Drain {
- deque: NonNull::from(&mut *self),
+ deque,
after_tail: drain_head,
after_head: head,
iter: Iter {
tail: drain_tail,
head: drain_head,
- ring: unsafe { self.buffer_as_mut_slice() },
+ ring: unsafe { (&mut *deque.as_ptr()).buffer_as_mut_slice() },
},
}
}