idk man..

src/tree.rs

@@ -206,6 +206,31 @@ impl<BorrowType: marker::BorrowType, K, V> Handle<NodeRef<BorrowType, K, V>, mar
     }
 }
 
+impl<K, V> NodeRef<marker::Dying, K, V> {
+    pub(super) fn deallocate_and_ascend(
+        self,
+    ) -> Option<Handle<NodeRef<marker::Dying, K, V>, marker::Edge>> {
+        let node = self.node;
+        let parent = self.ascend().ok();
+
+        unsafe {
+            match (*node.as_ptr()).capacity as usize {
+                0 => {}
+                capacity => {
+                    let keys = (*node.as_ptr()).keys;
+                    let edges = (*node.as_ptr()).edges;
+
+                    _ = Box::from_non_null(NonNull::slice_from_raw_parts(keys, capacity));
+                    _ = Box::from_non_null(NonNull::slice_from_raw_parts(edges, capacity));
+                }
+            }
+            _ = Box::from_non_null(node);
+        }
+
+        parent
+    }
+}
+
 impl<'a, K, V, HandleType> Handle<NodeRef<marker::Mut<'a>, K, V>, HandleType> {
     /// Temporarily takes out another mutable handle on the same location. Beware, as
     /// this method is very dangerous, doubly so since it might not immediately appear
@@ -518,6 +543,22 @@ impl<'a, K: 'a, V: 'a> Handle<NodeRef<marker::Immut<'a>, K, V>, marker::Value> {
     }
 }
 
+impl<K, V> NodeRef<marker::Dying, K, V> {
+    /// Borrows exclusive access to the leaf portion of a dying leaf or internal node.
+    fn as_leaf_dying(&mut self) -> &mut LeafNode<K, V> {
+        let ptr = Self::as_leaf_ptr(self);
+        // SAFETY: we have exclusive access to the entire node.
+        unsafe { &mut *ptr }
+    }
+}
+
+impl<K, V> NodeRef<marker::Dying, K, V> {
+    pub(super) unsafe fn into_value(mut self) -> Option<V> {
+        let leaf = self.as_leaf_dying();
+        leaf.value.take()
+    }
+}
+
 impl<'a, K: 'a, V: 'a> Handle<NodeRef<marker::Mut<'a>, K, V>, marker::Value> {
     pub(super) unsafe fn value_mut(&mut self) -> &mut V {
         let leaf = self.node.as_leaf_mut();
@@ -684,7 +725,7 @@ impl<'a, K: 'a, V: 'a> Handle<NodeRef<marker::Mut<'a>, K, V>, marker::Edge> {
 // search:
 
 mod search {
-    use super::{ForceResult, Handle, NodeRef, marker};
+    use super::{marker, ForceResult, Handle, NodeRef};
     use core::borrow::Borrow;
     use core::cmp::Ordering;
 
@@ -831,7 +872,7 @@ enum HandleOrTree<'a, BorrowType, K, V, HandleType> {
 mod entry {
     use core::marker::PhantomData;
 
-    use super::{Handle, NodeRef, marker};
+    use super::{marker, Handle, NodeRef};
 
     pub enum Entry<'a, Q: 'a, K: 'a, V: 'a>
     where
@@ -948,12 +989,11 @@ mod entry {
 mod subtree {
     use core::marker::PhantomData;
 
-    use crate::tree::{HandleOrTree, search};
+    use crate::tree::{search, HandleOrTree};
 
     use super::{
-        NodeRef, OnceAndIter,
         entry::{Entry, OccupiedEntry, VacantEntry},
-        marker,
+        marker, NodeRef, OnceAndIter,
     };
 
     // BorrowType may be one of `Immut`, `Mut`.