diff options
| -rw-r--r-- | library/alloc/src/collections/btree/node.rs | 21 |
1 files changed, 11 insertions, 10 deletions
diff --git a/library/alloc/src/collections/btree/node.rs b/library/alloc/src/collections/btree/node.rs index 22e60309a2c..0fec2b70a85 100644 --- a/library/alloc/src/collections/btree/node.rs +++ b/library/alloc/src/collections/btree/node.rs @@ -150,7 +150,7 @@ impl<K, V, Type> NodeRef<marker::Owned, K, V, Type> { /// Mutably borrows the owned node. Unlike `reborrow_mut`, this is safe, /// because the return value cannot be used to destroy the node itself, /// and there cannot be other references to the tree (except during the - /// process of `into_iter` or `drop`, but that is a horrific already). + /// process of `into_iter` or `drop`, but that is horrific already). pub fn borrow_mut(&mut self) -> NodeRef<marker::Mut<'_>, K, V, Type> { NodeRef { height: self.height, node: self.node, _marker: PhantomData } } @@ -192,7 +192,7 @@ impl<K, V> NodeRef<marker::Owned, K, V, marker::LeafOrInternal> { let internal_node = NodeRef { height: self.height, node: top, _marker: PhantomData }; *self = internal_node.first_edge().descend(); - self.borrow_mut().clear_parent_link(); + self.clear_parent_link(); unsafe { Global.deallocate(top.cast(), Layout::new::<InternalNode<K, V>>()); @@ -611,18 +611,19 @@ impl<'a, K: 'a, V: 'a, Type> NodeRef<marker::Mut<'a>, K, V, Type> { } impl<'a, K: 'a, V: 'a> NodeRef<marker::Mut<'a>, K, V, marker::LeafOrInternal> { - /// Set or clear the node's link to its parent edge, + /// Sets the node's link to its parent edge, /// without invalidating other references to the node. fn set_parent_link(&mut self, parent: NonNull<InternalNode<K, V>>, parent_idx: usize) { let leaf = Self::as_leaf_ptr(self); unsafe { (*leaf).parent = Some(parent) }; unsafe { (*leaf).parent_idx.write(parent_idx as u16) }; } +} - /// Clear the node's link to its parent edge. - /// This only makes sense when there are no other references to the node. +impl<K, V> NodeRef<marker::Owned, K, V, marker::LeafOrInternal> { + /// Clears the root's link to its parent edge. fn clear_parent_link(&mut self) { - let leaf = Self::as_leaf_mut(self); + let leaf = NodeRef::as_leaf_mut(&mut self.borrow_mut()); leaf.parent = None; } } @@ -720,9 +721,9 @@ impl<'a, K: 'a, V: 'a> NodeRef<marker::Mut<'a>, K, V, marker::LeafOrInternal> { ForceResult::Internal(internal) => { let node = ptr::read(internal.reborrow().edge_at(idx + 1)); let mut edge = Root { node, height: internal.height - 1, _marker: PhantomData }; - // In practice, clearing the parent is a waste of time, because we will + // Currently, clearing the parent link is superfluous, because we will // insert the node elsewhere and set its parent link again. - edge.borrow_mut().clear_parent_link(); + edge.clear_parent_link(); Some(edge) } }; @@ -748,9 +749,9 @@ impl<'a, K: 'a, V: 'a> NodeRef<marker::Mut<'a>, K, V, marker::LeafOrInternal> { ForceResult::Internal(mut internal) => { let node = slice_remove(internal.reborrow_mut().into_edge_area_slice(), 0); let mut edge = Root { node, height: internal.height - 1, _marker: PhantomData }; - // In practice, clearing the parent is a waste of time, because we will + // Currently, clearing the parent link is superfluous, because we will // insert the node elsewhere and set its parent link again. - edge.borrow_mut().clear_parent_link(); + edge.clear_parent_link(); internal.correct_childrens_parent_links(0..old_len); |