Upgrade intrusive-collections to 0.9.6 am: 5c2ecf697cHEADmastermain

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/intrusive-collections/+/2944845

Change-Id: I2592b7020b0031de4ecf47c9a8321d9111a42aa4
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>

13 files changed, 902 insertions, 217 deletions

diff --git a/.cargo_vcs_info.json b/.cargo_vcs_info.json
index b0613bc..57b2e50 100644
--- a/.cargo_vcs_info.json
+++ b/.cargo_vcs_info.json
@@ -1,6 +1,6 @@
 {
   "git": {
-    "sha1": "5b1d6a12c6eef1c94a94e5493cfb730edeee2ca2"
+    "sha1": "48ee32f2a00f8149d1fbff233007b0c82a54b47a"
   },
   "path_in_vcs": ""
 }
\ No newline at end of file
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 420045e..19bc32c 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -26,7 +26,6 @@ jobs:
       with:
         command: test
         args: --features nightly
-
   fmt:
     name: Rustfmt
     runs-on: ubuntu-latest
@@ -42,3 +41,15 @@ jobs:
         with:
           command: fmt
           args: -- --check
+  miri:
+    name: Miri
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions-rs/toolchain@v1
+        with:
+          profile: minimal
+          toolchain: nightly
+          override: true
+      - run: rustup component add miri
+      - run: cargo miri test --verbose --all-features
\ No newline at end of file
diff --git a/.gitignore b/.gitignore
index a9d37c5..9377bc1 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,3 @@
 target
 Cargo.lock
+.DS_Store
\ No newline at end of file
diff --git a/Android.bp b/Android.bp
index 6bc9c25..bf3b27c 100644
--- a/Android.bp
+++ b/Android.bp
@@ -44,7 +44,7 @@ rust_library {
     host_supported: true,
     crate_name: "intrusive_collections",
     cargo_env_compat: true,
-    cargo_pkg_version: "0.9.5",
+    cargo_pkg_version: "0.9.6",
     srcs: ["src/lib.rs"],
     edition: "2018",
     features: [
diff --git a/Cargo.toml b/Cargo.toml
index bec77d1..e60f7e3 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -12,7 +12,7 @@
 [package]
 edition = "2018"
 name = "intrusive-collections"
-version = "0.9.5"
+version = "0.9.6"
 authors = ["Amanieu d'Antras <amanieu@gmail.com>"]
 description = "Intrusive collections for Rust (linked list and red-black tree)"
 documentation = "https://docs.rs/intrusive-collections"
@@ -31,7 +31,7 @@ license = "Apache-2.0/MIT"
 repository = "https://github.com/Amanieu/intrusive-rs"
 
 [dependencies.memoffset]
-version = "0.8"
+version = "0.9"
 
 [dev-dependencies.rand]
 version = "0.8.4"
diff --git a/Cargo.toml.orig b/Cargo.toml.orig
index 5bd16b0..5d26514 100644
--- a/Cargo.toml.orig
+++ b/Cargo.toml.orig
@@ -1,6 +1,6 @@
 [package]
 name = "intrusive-collections"
-version = "0.9.5"
+version = "0.9.6"
 authors = ["Amanieu d'Antras <amanieu@gmail.com>"]
 description = "Intrusive collections for Rust (linked list and red-black tree)"
 documentation = "https://docs.rs/intrusive-collections"
@@ -17,7 +17,7 @@ alloc = []
 default = ["alloc"]
 
 [dependencies]
-memoffset = "0.8"
+memoffset = "0.9"
 
 [dev-dependencies]
 rand = "0.8.4"
diff --git a/METADATA b/METADATA
index 26d3f5e..1788616 100644
--- a/METADATA
+++ b/METADATA
@@ -1,23 +1,20 @@
 # This project was upgraded with external_updater.
-# Usage: tools/external_updater/updater.sh update rust/crates/intrusive-collections
-# For more info, check https://cs.android.com/android/platform/superproject/+/master:tools/external_updater/README.md
+# Usage: tools/external_updater/updater.sh update external/rust/crates/intrusive-collections
+# For more info, check https://cs.android.com/android/platform/superproject/+/main:tools/external_updater/README.md
 
 name: "intrusive-collections"
 description: "Intrusive collections for Rust (linked list and red-black tree)"
 third_party {
-  url {
-    type: HOMEPAGE
-    value: "https://crates.io/crates/intrusive-collections"
-  }
-  url {
-    type: ARCHIVE
-    value: "https://static.crates.io/crates/intrusive-collections/intrusive-collections-0.9.5.crate"
-  }
-  version: "0.9.5"
   license_type: NOTICE
   last_upgrade_date {
-    year: 2023
+    year: 2024
     month: 2
-    day: 16
+    day: 1
+  }
+  homepage: "https://crates.io/crates/intrusive-collections"
+  identifier {
+    type: "Archive"
+    value: "https://static.crates.io/crates/intrusive-collections/intrusive-collections-0.9.6.crate"
+    version: "0.9.6"
   }
 }
diff --git a/src/adapter.rs b/src/adapter.rs
index 5484a0f..9c21671 100644
--- a/src/adapter.rs
+++ b/src/adapter.rs
@@ -274,7 +274,6 @@ mod tests {
         link: LinkedListLink,
     }
 
-    #[deny(missing_docs)]
     intrusive_adapter! {
         /// Test doc comment
         ObjAdapter1 = Rc<Obj>: Obj { link: LinkedListLink }
diff --git a/src/linked_list.rs b/src/linked_list.rs
index efcdb8a..3d5c152 100644
--- a/src/linked_list.rs
+++ b/src/linked_list.rs
@@ -16,9 +16,11 @@ use core::sync::atomic::{AtomicPtr, Ordering};
 use crate::link_ops::{self, DefaultLinkOps};
 use crate::pointer_ops::PointerOps;
 use crate::singly_linked_list::SinglyLinkedListOps;
-use crate::unchecked_option::UncheckedOptionExt;
 use crate::xor_linked_list::XorLinkedListOps;
 use crate::Adapter;
+// Necessary for Rust 1.56 compatability
+#[allow(unused_imports)]
+use crate::unchecked_option::UncheckedOptionExt;
 
 // =============================================================================
 // LinkedListOps
@@ -581,7 +583,7 @@ unsafe fn splice<T: LinkedListOps>(
 }
 
 // =============================================================================
-// Cursor, CursorMut
+// Cursor, CursorMut, CursorOwning
 // =============================================================================
 
 /// A cursor which provides read-only access to a `LinkedList`.
@@ -636,7 +638,7 @@ where
     where
         <A::PointerOps as PointerOps>::Pointer: Clone,
     {
-        let raw_pointer = self.get()? as *const <A::PointerOps as PointerOps>::Value;
+        let raw_pointer = unsafe { self.list.adapter.get_value(self.current?) };
         Some(unsafe {
             crate::pointer_ops::clone_pointer_from_raw(self.list.adapter.pointer_ops(), raw_pointer)
         })
@@ -1064,6 +1066,61 @@ where
     }
 }
 
+/// A cursor with ownership over the `LinkedList` it points into.
+pub struct CursorOwning<A: Adapter>
+where
+    A::LinkOps: LinkedListOps,
+{
+    current: Option<<A::LinkOps as link_ops::LinkOps>::LinkPtr>,
+    list: LinkedList<A>,
+}
+
+impl<A: Adapter> CursorOwning<A>
+where
+    A::LinkOps: LinkedListOps,
+{
+    /// Consumes self and returns the inner `LinkedList`.
+    #[inline]
+    pub fn into_inner(self) -> LinkedList<A> {
+        self.list
+    }
+
+    /// Returns a read-only cursor pointing to the current element.
+    ///
+    /// The lifetime of the returned `Cursor` is bound to that of the
+    /// `CursorOwning`, which means it cannot outlive the `CursorOwning` and that the
+    /// `CursorOwning` is frozen for the lifetime of the `Cursor`.
+    ///
+    /// Mutations of the returned cursor are _not_ reflected in the original.
+    #[inline]
+    pub fn as_cursor(&self) -> Cursor<'_, A> {
+        Cursor {
+            current: self.current,
+            list: &self.list,
+        }
+    }
+
+    /// Perform action with mutable reference to the cursor.
+    ///
+    /// All mutations of the cursor are reflected in the original.
+    #[inline]
+    pub fn with_cursor_mut<T>(&mut self, f: impl FnOnce(&mut CursorMut<'_, A>) -> T) -> T {
+        let mut cursor = CursorMut {
+            current: self.current,
+            list: &mut self.list,
+        };
+        let ret = f(&mut cursor);
+        self.current = cursor.current;
+        ret
+    }
+}
+unsafe impl<A: Adapter> Send for CursorOwning<A>
+where
+    LinkedList<A>: Send,
+    A::LinkOps: LinkedListOps,
+{
+}
+
 // =============================================================================
 // LinkedList
 // =============================================================================
@@ -1153,6 +1210,15 @@ where
         }
     }
 
+    /// Returns a null `CursorOwning` for this list.
+    #[inline]
+    pub fn cursor_owning(self) -> CursorOwning<A> {
+        CursorOwning {
+            current: None,
+            list: self,
+        }
+    }
+
     /// Creates a `Cursor` from a pointer to an element.
     ///
     /// # Safety
@@ -1185,6 +1251,22 @@ where
         }
     }
 
+    /// Creates a `CursorOwning` from a pointer to an element.
+    ///
+    /// # Safety
+    ///
+    /// `ptr` must be a pointer to an object that is part of this list.
+    #[inline]
+    pub unsafe fn cursor_owning_from_ptr(
+        self,
+        ptr: *const <A::PointerOps as PointerOps>::Value,
+    ) -> CursorOwning<A> {
+        CursorOwning {
+            current: Some(self.adapter.get_link(ptr)),
+            list: self,
+        }
+    }
+
     /// Returns a `Cursor` pointing to the first element of the list. If the
     /// list is empty then a null cursor is returned.
     #[inline]
@@ -1203,6 +1285,15 @@ where
         cursor
     }
 
+    /// Returns a `CursorOwning` pointing to the first element of the list. If the
+    /// the list is empty then a null cursor is returned.
+    #[inline]
+    pub fn front_owning(self) -> CursorOwning<A> {
+        let mut cursor = self.cursor_owning();
+        cursor.with_cursor_mut(|c| c.move_next());
+        cursor
+    }
+
     /// Returns a `Cursor` pointing to the last element of the list. If the list
     /// is empty then a null cursor is returned.
     #[inline]
@@ -1221,6 +1312,15 @@ where
         cursor
     }
 
+    /// Returns a `CursorOwning` pointing to the last element of the list. If the
+    /// list is empty then a null cursor is returned.
+    #[inline]
+    pub fn back_owning(self) -> CursorOwning<A> {
+        let mut cursor = self.cursor_owning();
+        cursor.with_cursor_mut(|c| c.move_prev());
+        cursor
+    }
+
     /// Gets an iterator over the objects in the `LinkedList`.
     #[inline]
     pub fn iter(&self) -> Iter<'_, A> {
@@ -1487,7 +1587,11 @@ where
 
 #[cfg(test)]
 mod tests {
-    use super::{Link, LinkedList};
+    use alloc::boxed::Box;
+
+    use crate::UnsafeRef;
+
+    use super::{CursorOwning, Link, LinkedList};
     use std::fmt;
     use std::format;
     use std::rc::Rc;
@@ -1505,17 +1609,23 @@ mod tests {
     }
     intrusive_adapter!(ObjAdapter1 = Rc<Obj>: Obj { link1: Link });
     intrusive_adapter!(ObjAdapter2 = Rc<Obj>: Obj { link2: Link });
-    fn make_obj(value: u32) -> Rc<Obj> {
-        Rc::new(Obj {
+    intrusive_adapter!(UnsafeRefObjAdapter1 = UnsafeRef<Obj>: Obj { link1: Link });
+
+    fn make_rc_obj(value: u32) -> Rc<Obj> {
+        Rc::new(make_obj(value))
+    }
+
+    fn make_obj(value: u32) -> Obj {
+        Obj {
             link1: Link::new(),
             link2: Link::default(),
             value,
-        })
+        }
     }
 
     #[test]
     fn test_link() {
-        let a = make_obj(1);
+        let a = make_rc_obj(1);
         assert!(!a.link1.is_linked());
         assert!(!a.link2.is_linked());
 
@@ -1540,9 +1650,9 @@ mod tests {
 
     #[test]
     fn test_cursor() {
-        let a = make_obj(1);
-        let b = make_obj(2);
-        let c = make_obj(3);
+        let a = make_rc_obj(1);
+        let b = make_rc_obj(2);
+        let c = make_rc_obj(3);
 
         let mut l = LinkedList::new(ObjAdapter1::new());
         let mut cur = l.cursor_mut();
@@ -1622,10 +1732,36 @@ mod tests {
     }
 
     #[test]
+    fn test_cursor_owning() {
+        struct Container {
+            cur: CursorOwning<ObjAdapter1>,
+        }
+
+        let mut l = LinkedList::new(ObjAdapter1::new());
+        l.push_back(make_rc_obj(1));
+        l.push_back(make_rc_obj(2));
+        l.push_back(make_rc_obj(3));
+        l.push_back(make_rc_obj(4));
+        let mut con = Container {
+            cur: l.cursor_owning(),
+        };
+        assert!(con.cur.as_cursor().is_null());
+
+        con.cur = con.cur.into_inner().front_owning();
+        assert_eq!(con.cur.as_cursor().get().unwrap().value, 1);
+
+        con.cur.with_cursor_mut(|c| c.move_next());
+        assert_eq!(con.cur.as_cursor().get().unwrap().value, 2);
+
+        con.cur = con.cur.into_inner().back_owning();
+        assert_eq!(con.cur.as_cursor().get().unwrap().value, 4);
+    }
+
+    #[test]
     fn test_push_pop() {
-        let a = make_obj(1);
-        let b = make_obj(2);
-        let c = make_obj(3);
+        let a = make_rc_obj(1);
+        let b = make_rc_obj(2);
+        let c = make_rc_obj(3);
 
         let mut l = LinkedList::new(ObjAdapter1::new());
         l.push_front(a);
@@ -1652,10 +1788,10 @@ mod tests {
         let mut l2 = LinkedList::new(ObjAdapter1::new());
         let mut l3 = LinkedList::new(ObjAdapter1::new());
 
-        let a = make_obj(1);
-        let b = make_obj(2);
-        let c = make_obj(3);
-        let d = make_obj(4);
+        let a = make_rc_obj(1);
+        let b = make_rc_obj(2);
+        let c = make_rc_obj(3);
+        let d = make_rc_obj(4);
         l1.cursor_mut().insert_before(a);
         l1.cursor_mut().insert_before(b);
         l1.cursor_mut().insert_before(c);
@@ -1740,10 +1876,10 @@ mod tests {
     #[test]
     fn test_iter() {
         let mut l = LinkedList::new(ObjAdapter1::new());
-        let a = make_obj(1);
-        let b = make_obj(2);
-        let c = make_obj(3);
-        let d = make_obj(4);
+        let a = make_rc_obj(1);
+        let b = make_rc_obj(2);
+        let c = make_rc_obj(3);
+        let d = make_rc_obj(4);
         l.cursor_mut().insert_before(a.clone());
         l.cursor_mut().insert_before(b.clone());
         l.cursor_mut().insert_before(c.clone());
@@ -1814,10 +1950,10 @@ mod tests {
     fn test_multi_list() {
         let mut l1 = LinkedList::new(ObjAdapter1::new());
         let mut l2 = LinkedList::new(ObjAdapter2::new());
-        let a = make_obj(1);
-        let b = make_obj(2);
-        let c = make_obj(3);
-        let d = make_obj(4);
+        let a = make_rc_obj(1);
+        let b = make_rc_obj(2);
+        let c = make_rc_obj(3);
+        let d = make_rc_obj(4);
         l1.cursor_mut().insert_before(a.clone());
         l1.cursor_mut().insert_before(b.clone());
         l1.cursor_mut().insert_before(c.clone());
@@ -1831,29 +1967,39 @@ mod tests {
     }
 
     #[test]
-    fn test_force_unlink() {
-        let mut l = LinkedList::new(ObjAdapter1::new());
-        let a = make_obj(1);
-        let b = make_obj(2);
-        let c = make_obj(3);
+    fn test_fast_clear_force_unlink() {
+        let mut l = LinkedList::new(UnsafeRefObjAdapter1::new());
+        let a = UnsafeRef::from_box(Box::new(make_obj(1)));
+        let b = UnsafeRef::from_box(Box::new(make_obj(2)));
+        let c = UnsafeRef::from_box(Box::new(make_obj(3)));
         l.cursor_mut().insert_before(a.clone());
         l.cursor_mut().insert_before(b.clone());
         l.cursor_mut().insert_before(c.clone());
 
         l.fast_clear();
         assert!(l.is_empty());
-        assert!(a.link1.is_linked());
-        assert!(b.link1.is_linked());
-        assert!(c.link1.is_linked());
+
         unsafe {
+            assert!(a.link1.is_linked());
+            assert!(b.link1.is_linked());
+            assert!(c.link1.is_linked());
+
             a.link1.force_unlink();
             b.link1.force_unlink();
             c.link1.force_unlink();
+
+            assert!(l.is_empty());
+
+            assert!(!a.link1.is_linked());
+            assert!(!b.link1.is_linked());
+            assert!(!c.link1.is_linked());
+        }
+
+        unsafe {
+            UnsafeRef::into_box(a);
+            UnsafeRef::into_box(b);
+            UnsafeRef::into_box(c);
         }
-        assert!(l.is_empty());
-        assert!(!a.link1.is_linked());
-        assert!(!b.link1.is_linked());
-        assert!(!c.link1.is_linked());
     }
 
     #[test]
diff --git a/src/pointer_ops.rs b/src/pointer_ops.rs
index 716ac15..1d566ed 100644
--- a/src/pointer_ops.rs
+++ b/src/pointer_ops.rs
@@ -374,7 +374,7 @@ mod tests {
         unsafe {
             let pointer_ops = DefaultPointerOps::<Arc<_>>::new();
             let p = Arc::new(1);
-            let raw = &*p as *const i32;
+            let raw = Arc::as_ptr(&p);
             let p2: Arc<i32> = clone_pointer_from_raw(&pointer_ops, raw);
             assert_eq!(2, Arc::strong_count(&p2));
         }
@@ -386,7 +386,7 @@ mod tests {
         unsafe {
             let pointer_ops = DefaultPointerOps::<Rc<_>>::new();
             let p = Rc::new(1);
-            let raw = &*p as *const i32;
+            let raw = Rc::as_ptr(&p);
             let p2: Rc<i32> = clone_pointer_from_raw(&pointer_ops, raw);
             assert_eq!(2, Rc::strong_count(&p2));
         }
@@ -491,8 +491,9 @@ mod tests {
         unsafe {
             let pointer_ops = DefaultPointerOps::<Pin<Arc<_>>>::new();
             let p = Pin::new(Arc::new(1));
-            let raw = &*p as *const i32;
+            let raw = pointer_ops.into_raw(p);
             let p2: Pin<Arc<i32>> = clone_pointer_from_raw(&pointer_ops, raw);
+            let _p = pointer_ops.from_raw(raw);
             assert_eq!(2, Arc::strong_count(&Pin::into_inner(p2)));
         }
     }
@@ -503,8 +504,9 @@ mod tests {
         unsafe {
             let pointer_ops = DefaultPointerOps::<Pin<Rc<_>>>::new();
             let p = Pin::new(Rc::new(1));
-            let raw = &*p as *const i32;
+            let raw = pointer_ops.into_raw(p);
             let p2: Pin<Rc<i32>> = clone_pointer_from_raw(&pointer_ops, raw);
+            let _p = pointer_ops.from_raw(raw);
             assert_eq!(2, Rc::strong_count(&Pin::into_inner(p2)));
         }
     }
diff --git a/src/rbtree.rs b/src/rbtree.rs
index 87badec..83d428e 100644
--- a/src/rbtree.rs
+++ b/src/rbtree.rs
@@ -22,10 +22,12 @@ use crate::link_ops::{self, DefaultLinkOps};
 use crate::linked_list::LinkedListOps;
 use crate::pointer_ops::PointerOps;
 use crate::singly_linked_list::SinglyLinkedListOps;
-use crate::unchecked_option::UncheckedOptionExt;
 use crate::xor_linked_list::XorLinkedListOps;
 use crate::Adapter;
 use crate::KeyAdapter;
+// Necessary for Rust 1.56 compatability
+#[allow(unused_imports)]
+use crate::unchecked_option::UncheckedOptionExt;
 
 // =============================================================================
 // RBTreeOps
@@ -1037,7 +1039,7 @@ unsafe fn remove<T: RBTreeOps>(link_ops: &mut T, ptr: T::LinkPtr, root: &mut Opt
 }
 
 // =============================================================================
-// Cursor, CursorMut
+// Cursor, CursorMut, CursorOwning
 // =============================================================================
 
 /// A cursor which provides read-only access to a `RBTree`.
@@ -1092,7 +1094,7 @@ where
     where
         <A::PointerOps as PointerOps>::Pointer: Clone,
     {
-        let raw_pointer = self.get()? as *const <A::PointerOps as PointerOps>::Value;
+        let raw_pointer = unsafe { self.tree.adapter.get_value(self.current?) };
         Some(unsafe {
             crate::pointer_ops::clone_pointer_from_raw(self.tree.adapter.pointer_ops(), raw_pointer)
         })
@@ -1449,6 +1451,61 @@ where
     }
 }
 
+/// A cursor with ownership over the `RBTree` it points into.
+pub struct CursorOwning<A: Adapter>
+where
+    A::LinkOps: RBTreeOps,
+{
+    current: Option<<A::LinkOps as link_ops::LinkOps>::LinkPtr>,
+    tree: RBTree<A>,
+}
+
+impl<A: Adapter> CursorOwning<A>
+where
+    A::LinkOps: RBTreeOps,
+{
+    /// Consumes self and returns the inner `RBTree`.
+    #[inline]
+    pub fn into_inner(self) -> RBTree<A> {
+        self.tree
+    }
+
+    /// Returns a read-only cursor pointing to the current element.
+    ///
+    /// The lifetime of the returned `Cursor` is bound to that of the
+    /// `CursorOwning`, which means it cannot outlive the `CursorOwning` and that the
+    /// `CursorOwning` is frozen for the lifetime of the `Cursor`.
+    ///
+    /// Mutations of the returned cursor are _not_ reflected in the original.
+    #[inline]
+    pub fn as_cursor(&self) -> Cursor<'_, A> {
+        Cursor {
+            current: self.current,
+            tree: &self.tree,
+        }
+    }
+
+    /// Perform action with mutable reference to the cursor.
+    ///
+    /// All mutations of the cursor are reflected in the original.
+    #[inline]
+    pub fn with_cursor_mut<T>(&mut self, f: impl FnOnce(&mut CursorMut<'_, A>) -> T) -> T {
+        let mut cursor = CursorMut {
+            current: self.current,
+            tree: &mut self.tree,
+        };
+        let ret = f(&mut cursor);
+        self.current = cursor.current;
+        ret
+    }
+}
+unsafe impl<A: Adapter> Send for CursorOwning<A>
+where
+    RBTree<A>: Send,
+    A::LinkOps: RBTreeOps,
+{
+}
+
 // =============================================================================
 // RBTree
 // =============================================================================
@@ -1542,6 +1599,15 @@ where
         }
     }
 
+    /// Returns a null `CursorOwning` for this tree.
+    #[inline]
+    pub fn cursor_owning(self) -> CursorOwning<A> {
+        CursorOwning {
+            current: None,
+            tree: self,
+        }
+    }
+
     /// Creates a `Cursor` from a pointer to an element.
     ///
     /// # Safety
@@ -1574,6 +1640,22 @@ where
         }
     }
 
+    /// Creates a `CursorOwning` from a pointer to an element.
+    ///
+    /// # Safety
+    ///
+    /// `ptr` must be a pointer to an object that is part of this tree.
+    #[inline]
+    pub unsafe fn cursor_owning_from_ptr(
+        self,
+        ptr: *const <A::PointerOps as PointerOps>::Value,
+    ) -> CursorOwning<A> {
+        CursorOwning {
+            current: Some(self.adapter.get_link(ptr)),
+            tree: self,
+        }
+    }
+
     /// Returns a `Cursor` pointing to the first element of the tree. If the
     /// tree is empty then a null cursor is returned.
     #[inline]
@@ -1592,6 +1674,15 @@ where
         cursor
     }
 
+    /// Returns a `CursorOwning` pointing to the first element of the tree. If the
+    /// the tree is empty then a null cursor is returned.
+    #[inline]
+    pub fn front_owning(self) -> CursorOwning<A> {
+        let mut cursor = self.cursor_owning();
+        cursor.with_cursor_mut(|c| c.move_next());
+        cursor
+    }
+
     /// Returns a `Cursor` pointing to the last element of the tree. If the tree
     /// is empty then a null cursor is returned.
     #[inline]
@@ -1610,6 +1701,15 @@ where
         cursor
     }
 
+    /// Returns a `CursorOwning` pointing to the last element of the tree. If the
+    /// tree is empty then a null cursor is returned.
+    #[inline]
+    pub fn back_owning(self) -> CursorOwning<A> {
+        let mut cursor = self.cursor_owning();
+        cursor.with_cursor_mut(|c| c.move_prev());
+        cursor
+    }
+
     #[inline]
     unsafe fn insert_root(&mut self, node: <A::LinkOps as link_ops::LinkOps>::LinkPtr) {
         self.adapter.link_ops_mut().set_parent(node, None);
@@ -1758,6 +1858,23 @@ where
         }
     }
 
+    // Returns a `CursorOwning` pointing to an element with the given key. If no
+    /// such element is found then a null cursor is returned.
+    ///
+    /// If multiple elements with an identical key are found then an arbitrary
+    /// one is returned.
+    #[inline]
+    pub fn find_owning<'a, Q: ?Sized + Ord>(self, key: &Q) -> CursorOwning<A>
+    where
+        <A as KeyAdapter<'a>>::Key: Borrow<Q>,
+        Self: 'a,
+    {
+        CursorOwning {
+            current: self.find_internal(key),
+            tree: self,
+        }
+    }
+
     #[inline]
     fn lower_bound_internal<'a, Q: ?Sized + Ord>(
         &self,
@@ -1821,6 +1938,21 @@ where
         }
     }
 
+    /// Returns a `CursorOwning` pointing to the first element whose key is
+    /// above the given bound. If no such element is found then a null
+    /// cursor is returned.
+    #[inline]
+    pub fn lower_bound_owning<'a, Q: ?Sized + Ord>(self, bound: Bound<&Q>) -> CursorOwning<A>
+    where
+        <A as KeyAdapter<'a>>::Key: Borrow<Q>,
+        Self: 'a,
+    {
+        CursorOwning {
+            current: self.lower_bound_internal(bound),
+            tree: self,
+        }
+    }
+
     #[inline]
     fn upper_bound_internal<'a, Q: ?Sized + Ord>(
         &self,
@@ -1884,6 +2016,21 @@ where
         }
     }
 
+    /// Returns a `CursorOwning` pointing to the last element whose key is
+    /// below the given bound. If no such element is found then a null
+    /// cursor is returned.
+    #[inline]
+    pub fn upper_bound_owning<'a, Q: ?Sized + Ord>(self, bound: Bound<&Q>) -> CursorOwning<A>
+    where
+        <A as KeyAdapter<'a>>::Key: Borrow<Q>,
+        Self: 'a,
+    {
+        CursorOwning {
+            current: self.upper_bound_internal(bound),
+            tree: self,
+        }
+    }
+
     /// Inserts a new element into the `RBTree`.
     ///
     /// The new element will be inserted at the correct position in the tree
@@ -1927,6 +2074,7 @@ where
             } else {
                 self.insert_root(new);
             }
+
             CursorMut {
                 current: Some(new),
                 tree: self,
@@ -2382,8 +2530,9 @@ where
 
 #[cfg(test)]
 mod tests {
-    use super::{Entry, KeyAdapter, Link, PointerOps, RBTree};
-    use crate::Bound::*;
+    use super::{CursorOwning, Entry, KeyAdapter, Link, PointerOps, RBTree};
+    use crate::{Bound::*, UnsafeRef};
+    use alloc::boxed::Box;
     use rand::prelude::*;
     use rand_xorshift::XorShiftRng;
     use std::fmt;
@@ -2401,27 +2550,42 @@ mod tests {
             write!(f, "{}", self.value)
         }
     }
-    intrusive_adapter!(ObjAdapter = Rc<Obj>: Obj { link: Link });
-    impl<'a> KeyAdapter<'a> for ObjAdapter {
+    intrusive_adapter!(RcObjAdapter = Rc<Obj>: Obj { link: Link });
+
+    impl<'a> KeyAdapter<'a> for RcObjAdapter {
         type Key = i32;
         fn get_key(&self, value: &'a <Self::PointerOps as PointerOps>::Value) -> i32 {
             value.value
         }
     }
-    fn make_obj(value: i32) -> Rc<Obj> {
-        Rc::new(Obj {
+
+    intrusive_adapter!(UnsafeRefObjAdapter = UnsafeRef<Obj>: Obj { link: Link });
+
+    impl<'a> KeyAdapter<'a> for UnsafeRefObjAdapter {
+        type Key = i32;
+        fn get_key(&self, value: &'a <Self::PointerOps as PointerOps>::Value) -> i32 {
+            value.value
+        }
+    }
+
+    fn make_rc_obj(value: i32) -> Rc<Obj> {
+        Rc::new(make_obj(value))
+    }
+
+    fn make_obj(value: i32) -> Obj {
+        Obj {
             link: Link::new(),
             value,
-        })
+        }
     }
 
     #[test]
     fn test_link() {
-        let a = make_obj(1);
+        let a = make_rc_obj(1);
         assert!(!a.link.is_linked());
         assert_eq!(format!("{:?}", a.link), "unlinked");
 
-        let mut b = RBTree::<ObjAdapter>::default();
+        let mut b = RBTree::<RcObjAdapter>::default();
         assert!(b.is_empty());
 
         assert_eq!(b.insert(a.clone()).get().unwrap().value, 1);
@@ -2447,10 +2611,10 @@ mod tests {
 
     #[test]
     fn test_cursor() {
-        let a = make_obj(1);
-        let b = make_obj(2);
-        let c = make_obj(3);
-        let mut t = RBTree::new(ObjAdapter::new());
+        let a = make_rc_obj(1);
+        let b = make_rc_obj(2);
+        let c = make_rc_obj(3);
+        let mut t = RBTree::new(RcObjAdapter::new());
         let mut cur = t.cursor_mut();
         assert!(cur.is_null());
         assert!(cur.get().is_none());
@@ -2488,9 +2652,9 @@ mod tests {
         }
         assert_eq!(cur.get().unwrap() as *const _, a.as_ref() as *const _);
 
-        let a2 = make_obj(1);
-        let b2 = make_obj(2);
-        let c2 = make_obj(3);
+        let a2 = make_rc_obj(1);
+        let b2 = make_rc_obj(2);
+        let c2 = make_rc_obj(3);
         assert_eq!(
             cur.replace_with(a2).unwrap().as_ref() as *const _,
             a.as_ref() as *const _
@@ -2515,12 +2679,41 @@ mod tests {
         );
     }
 
-    #[cfg(not(miri))]
+    #[test]
+    fn test_cursor_owning() {
+        struct Container {
+            cur: CursorOwning<RcObjAdapter>,
+        }
+
+        let mut t = RBTree::new(RcObjAdapter::new());
+        t.insert(make_rc_obj(1));
+        t.insert(make_rc_obj(2));
+        t.insert(make_rc_obj(3));
+        t.insert(make_rc_obj(4));
+        let mut con = Container {
+            cur: t.cursor_owning(),
+        };
+        assert!(con.cur.as_cursor().is_null());
+
+        con.cur = con.cur.into_inner().front_owning();
+        assert_eq!(con.cur.as_cursor().get().unwrap().value, 1);
+
+        con.cur = con.cur.into_inner().back_owning();
+        assert_eq!(con.cur.as_cursor().get().unwrap().value, 4);
+
+        con.cur = con.cur.into_inner().find_owning(&2);
+        assert_eq!(con.cur.as_cursor().get().unwrap().value, 2);
+
+        con.cur.with_cursor_mut(|c| c.move_next());
+        assert_eq!(con.cur.as_cursor().get().unwrap().value, 3);
+    }
+
     #[test]
     fn test_insert_remove() {
-        let v = (0..100).map(make_obj).collect::<Vec<_>>();
+        let len = if cfg!(miri) { 10 } else { 100 };
+        let v = (0..len).map(make_rc_obj).collect::<Vec<_>>();
         assert!(v.iter().all(|x| !x.link.is_linked()));
-        let mut t = RBTree::new(ObjAdapter::new());
+        let mut t = RBTree::new(RcObjAdapter::new());
         assert!(t.is_empty());
         let mut rng = XorShiftRng::seed_from_u64(0);
 
@@ -2635,11 +2828,10 @@ mod tests {
         }
     }
 
-    #[cfg(not(miri))]
     #[test]
     fn test_iter() {
-        let v = (0..10).map(|x| make_obj(x * 10)).collect::<Vec<_>>();
-        let mut t = RBTree::new(ObjAdapter::new());
+        let v = (0..10).map(|x| make_rc_obj(x * 10)).collect::<Vec<_>>();
+        let mut t = RBTree::new(RcObjAdapter::new());
         for x in v.iter() {
             t.insert(x.clone());
         }
@@ -2884,8 +3076,8 @@ mod tests {
 
     #[test]
     fn test_find() {
-        let v = (0..10).map(|x| make_obj(x * 10)).collect::<Vec<_>>();
-        let mut t = RBTree::new(ObjAdapter::new());
+        let v = (0..10).map(|x| make_rc_obj(x * 10)).collect::<Vec<_>>();
+        let mut t = RBTree::new(RcObjAdapter::new());
         for x in v.iter() {
             t.insert(x.clone());
         }
@@ -3012,40 +3204,50 @@ mod tests {
     }
 
     #[test]
-    fn test_fast_clear() {
-        let mut t = RBTree::new(ObjAdapter::new());
-        let a = make_obj(1);
-        let b = make_obj(2);
-        let c = make_obj(3);
+    fn test_fast_clear_force_unlink() {
+        let mut t = RBTree::new(UnsafeRefObjAdapter::new());
+        let a = UnsafeRef::from_box(Box::new(make_obj(1)));
+        let b = UnsafeRef::from_box(Box::new(make_obj(2)));
+        let c = UnsafeRef::from_box(Box::new(make_obj(3)));
         t.insert(a.clone());
         t.insert(b.clone());
         t.insert(c.clone());
 
         t.fast_clear();
         assert!(t.is_empty());
-        assert!(a.link.is_linked());
-        assert!(b.link.is_linked());
-        assert!(c.link.is_linked());
+
         unsafe {
+            assert!(a.link.is_linked());
+            assert!(b.link.is_linked());
+            assert!(c.link.is_linked());
+
             a.link.force_unlink();
             b.link.force_unlink();
             c.link.force_unlink();
+
+            assert!(t.is_empty());
+
+            assert!(!a.link.is_linked());
+            assert!(!b.link.is_linked());
+            assert!(!c.link.is_linked());
+        }
+
+        unsafe {
+            UnsafeRef::into_box(a);
+            UnsafeRef::into_box(b);
+            UnsafeRef::into_box(c);
         }
-        assert!(t.is_empty());
-        assert!(!a.link.is_linked());
-        assert!(!b.link.is_linked());
-        assert!(!c.link.is_linked());
     }
 
     #[test]
     fn test_entry() {
-        let mut t = RBTree::new(ObjAdapter::new());
-        let a = make_obj(1);
-        let b = make_obj(2);
-        let c = make_obj(3);
-        let d = make_obj(4);
-        let e = make_obj(5);
-        let f = make_obj(6);
+        let mut t = RBTree::new(RcObjAdapter::new());
+        let a = make_rc_obj(1);
+        let b = make_rc_obj(2);
+        let c = make_rc_obj(3);
+        let d = make_rc_obj(4);
+        let e = make_rc_obj(5);
+        let f = make_rc_obj(6);
         t.entry(&3).or_insert(c);
         t.entry(&2).or_insert(b.clone());
         t.entry(&1).or_insert(a);
@@ -3089,8 +3291,8 @@ mod tests {
             link: Link,
             value: &'a T,
         }
-        intrusive_adapter!(ObjAdapter<'a, T> = &'a Obj<'a, T>: Obj<'a, T> {link: Link} where T: 'a);
-        impl<'a, 'b, T: 'a + 'b> KeyAdapter<'a> for ObjAdapter<'b, T> {
+        intrusive_adapter!(RcObjAdapter<'a, T> = &'a Obj<'a, T>: Obj<'a, T> {link: Link} where T: 'a);
+        impl<'a, 'b, T: 'a + 'b> KeyAdapter<'a> for RcObjAdapter<'b, T> {
             type Key = &'a T;
             fn get_key(&self, value: &'a Obj<'b, T>) -> &'a T {
                 value.value
@@ -3103,7 +3305,7 @@ mod tests {
             value: &v,
         };
         let b = a.clone();
-        let mut l = RBTree::new(ObjAdapter::new());
+        let mut l = RBTree::new(RcObjAdapter::new());
         l.insert(&a);
         l.insert(&b);
         assert_eq!(*l.front().get().unwrap().value, 5);
@@ -3119,8 +3321,8 @@ mod tests {
                 link: Link,
                 value: usize,
             }
-            intrusive_adapter!(ObjAdapter = $ptr<Obj>: Obj { link: Link });
-            impl<'a> KeyAdapter<'a> for ObjAdapter {
+            intrusive_adapter!(RcObjAdapter = $ptr<Obj>: Obj { link: Link });
+            impl<'a> KeyAdapter<'a> for RcObjAdapter {
                 type Key = usize;
                 fn get_key(&self, value: &'a Obj) -> usize {
                     value.value
@@ -3131,7 +3333,7 @@ mod tests {
                 link: Link::new(),
                 value: 5,
             });
-            let mut l = RBTree::new(ObjAdapter::new());
+            let mut l = RBTree::new(RcObjAdapter::new());
             l.insert(a.clone());
             assert_eq!(2, $ptr::strong_count(&a));
 
diff --git a/src/singly_linked_list.rs b/src/singly_linked_list.rs
index fb0618e..cf66418 100644
--- a/src/singly_linked_list.rs
+++ b/src/singly_linked_list.rs
@@ -497,7 +497,7 @@ unsafe fn splice<T: SinglyLinkedListOps>(
 }
 
 // =============================================================================
-// Cursor, CursorMut
+// Cursor, CursorMut, CursorOwning
 // =============================================================================
 
 /// A cursor which provides read-only access to a `SinglyLinkedList`.
@@ -552,7 +552,7 @@ where
     where
         <A::PointerOps as PointerOps>::Pointer: Clone,
     {
-        let raw_pointer = self.get()? as *const <A::PointerOps as PointerOps>::Value;
+        let raw_pointer = unsafe { self.list.adapter.get_value(self.current?) };
         Some(unsafe {
             crate::pointer_ops::clone_pointer_from_raw(self.list.adapter.pointer_ops(), raw_pointer)
         })
@@ -840,6 +840,61 @@ where
     }
 }
 
+/// A cursor with ownership over the `SinglyLinkedList` it points into.
+pub struct CursorOwning<A: Adapter>
+where
+    A::LinkOps: SinglyLinkedListOps,
+{
+    current: Option<<A::LinkOps as link_ops::LinkOps>::LinkPtr>,
+    list: SinglyLinkedList<A>,
+}
+
+impl<A: Adapter> CursorOwning<A>
+where
+    A::LinkOps: SinglyLinkedListOps,
+{
+    /// Consumes self and returns the inner `SinglyLinkedList`.
+    #[inline]
+    pub fn into_inner(self) -> SinglyLinkedList<A> {
+        self.list
+    }
+
+    /// Returns a read-only cursor pointing to the current element.
+    ///
+    /// The lifetime of the returned `Cursor` is bound to that of the
+    /// `CursorOwning`, which means it cannot outlive the `CursorOwning` and that the
+    /// `CursorOwning` is frozen for the lifetime of the `Cursor`.
+    ///
+    /// Mutations of the returned cursor are _not_ reflected in the original.
+    #[inline]
+    pub fn as_cursor(&self) -> Cursor<'_, A> {
+        Cursor {
+            current: self.current,
+            list: &self.list,
+        }
+    }
+
+    /// Perform action with mutable reference to the cursor.
+    ///
+    /// All mutations of the cursor are reflected in the original.
+    #[inline]
+    pub fn with_cursor_mut<T>(&mut self, f: impl FnOnce(&mut CursorMut<'_, A>) -> T) -> T {
+        let mut cursor = CursorMut {
+            current: self.current,
+            list: &mut self.list,
+        };
+        let ret = f(&mut cursor);
+        self.current = cursor.current;
+        ret
+    }
+}
+unsafe impl<A: Adapter> Send for CursorOwning<A>
+where
+    SinglyLinkedList<A>: Send,
+    A::LinkOps: SinglyLinkedListOps,
+{
+}
+
 // =============================================================================
 // SinglyLinkedList
 // =============================================================================
@@ -926,6 +981,15 @@ where
         }
     }
 
+    /// Returns a null `CursorOwning` for this list.
+    #[inline]
+    pub fn cursor_owning(self) -> CursorOwning<A> {
+        CursorOwning {
+            current: None,
+            list: self,
+        }
+    }
+
     /// Creates a `Cursor` from a pointer to an element.
     ///
     /// # Safety
@@ -958,6 +1022,22 @@ where
         }
     }
 
+    /// Creates a `CursorOwning` from a pointer to an element.
+    ///
+    /// # Safety
+    ///
+    /// `ptr` must be a pointer to an object that is part of this list.
+    #[inline]
+    pub unsafe fn cursor_owning_from_ptr(
+        self,
+        ptr: *const <A::PointerOps as PointerOps>::Value,
+    ) -> CursorOwning<A> {
+        CursorOwning {
+            current: Some(self.adapter.get_link(ptr)),
+            list: self,
+        }
+    }
+
     /// Returns a `Cursor` pointing to the first element of the list. If the
     /// list is empty then a null cursor is returned.
     #[inline]
@@ -976,6 +1056,15 @@ where
         cursor
     }
 
+    /// Returns a `CursorOwning` pointing to the first element of the list. If the
+    /// the list is empty then a null cursor is returned.
+    #[inline]
+    pub fn front_owning(self) -> CursorOwning<A> {
+        let mut cursor = self.cursor_owning();
+        cursor.with_cursor_mut(|c| c.move_next());
+        cursor
+    }
+
     /// Gets an iterator over the objects in the `SinglyLinkedList`.
     #[inline]
     pub fn iter(&self) -> Iter<'_, A> {
@@ -1190,7 +1279,11 @@ where
 
 #[cfg(test)]
 mod tests {
-    use super::{Link, SinglyLinkedList};
+    use alloc::boxed::Box;
+
+    use crate::UnsafeRef;
+
+    use super::{CursorOwning, Link, SinglyLinkedList};
     use std::fmt;
     use std::format;
     use std::rc::Rc;
@@ -1206,23 +1299,28 @@ mod tests {
             write!(f, "{}", self.value)
         }
     }
-    intrusive_adapter!(ObjAdapter1 = Rc<Obj>: Obj { link1: Link });
-    intrusive_adapter!(ObjAdapter2 = Rc<Obj>: Obj { link2: Link });
-    fn make_obj(value: u32) -> Rc<Obj> {
-        Rc::new(Obj {
+    intrusive_adapter!(RcObjAdapter1 = Rc<Obj>: Obj { link1: Link });
+    intrusive_adapter!(RcObjAdapter2 = Rc<Obj>: Obj { link2: Link });
+    intrusive_adapter!(UnsafeRefObjAdapter1 = UnsafeRef<Obj>: Obj { link1: Link });
+
+    fn make_rc_obj(value: u32) -> Rc<Obj> {
+        Rc::new(make_obj(value))
+    }
+    fn make_obj(value: u32) -> Obj {
+        Obj {
             link1: Link::new(),
             link2: Link::default(),
             value,
-        })
+        }
     }
 
     #[test]
     fn test_link() {
-        let a = make_obj(1);
+        let a = make_rc_obj(1);
         assert!(!a.link1.is_linked());
         assert!(!a.link2.is_linked());
 
-        let mut b = SinglyLinkedList::<ObjAdapter1>::default();
+        let mut b = SinglyLinkedList::<RcObjAdapter1>::default();
         assert!(b.is_empty());
 
         b.push_front(a.clone());
@@ -1243,11 +1341,11 @@ mod tests {
 
     #[test]
     fn test_cursor() {
-        let a = make_obj(1);
-        let b = make_obj(2);
-        let c = make_obj(3);
+        let a = make_rc_obj(1);
+        let b = make_rc_obj(2);
+        let c = make_rc_obj(3);
 
-        let mut l = SinglyLinkedList::new(ObjAdapter1::new());
+        let mut l = SinglyLinkedList::new(RcObjAdapter1::new());
         let mut cur = l.cursor_mut();
         assert!(cur.is_null());
         assert!(cur.get().is_none());
@@ -1323,15 +1421,38 @@ mod tests {
     }
 
     #[test]
+    fn test_cursor_owning() {
+        struct Container {
+            cur: CursorOwning<RcObjAdapter1>,
+        }
+
+        let mut l = SinglyLinkedList::new(RcObjAdapter1::new());
+        l.push_front(make_rc_obj(1));
+        l.push_front(make_rc_obj(2));
+        l.push_front(make_rc_obj(3));
+        l.push_front(make_rc_obj(4));
+        let mut con = Container {
+            cur: l.cursor_owning(),
+        };
+        assert!(con.cur.as_cursor().is_null());
+
+        con.cur = con.cur.into_inner().front_owning();
+        assert_eq!(con.cur.as_cursor().get().unwrap().value, 4);
+
+        con.cur.with_cursor_mut(|c| c.move_next());
+        assert_eq!(con.cur.as_cursor().get().unwrap().value, 3);
+    }
+
+    #[test]
     fn test_split_splice() {
-        let mut l1 = SinglyLinkedList::new(ObjAdapter1::new());
-        let mut l2 = SinglyLinkedList::new(ObjAdapter1::new());
-        let mut l3 = SinglyLinkedList::new(ObjAdapter1::new());
-
-        let a = make_obj(1);
-        let b = make_obj(2);
-        let c = make_obj(3);
-        let d = make_obj(4);
+        let mut l1 = SinglyLinkedList::new(RcObjAdapter1::new());
+        let mut l2 = SinglyLinkedList::new(RcObjAdapter1::new());
+        let mut l3 = SinglyLinkedList::new(RcObjAdapter1::new());
+
+        let a = make_rc_obj(1);
+        let b = make_rc_obj(2);
+        let c = make_rc_obj(3);
+        let d = make_rc_obj(4);
         l1.cursor_mut().insert_after(d);
         l1.cursor_mut().insert_after(c);
         l1.cursor_mut().insert_after(b);
@@ -1417,11 +1538,11 @@ mod tests {
 
     #[test]
     fn test_iter() {
-        let mut l = SinglyLinkedList::new(ObjAdapter1::new());
-        let a = make_obj(1);
-        let b = make_obj(2);
-        let c = make_obj(3);
-        let d = make_obj(4);
+        let mut l = SinglyLinkedList::new(RcObjAdapter1::new());
+        let a = make_rc_obj(1);
+        let b = make_rc_obj(2);
+        let c = make_rc_obj(3);
+        let d = make_rc_obj(4);
         l.cursor_mut().insert_after(d.clone());
         l.cursor_mut().insert_after(c.clone());
         l.cursor_mut().insert_after(b.clone());
@@ -1471,12 +1592,12 @@ mod tests {
 
     #[test]
     fn test_multi_list() {
-        let mut l1 = SinglyLinkedList::new(ObjAdapter1::new());
-        let mut l2 = SinglyLinkedList::new(ObjAdapter2::new());
-        let a = make_obj(1);
-        let b = make_obj(2);
-        let c = make_obj(3);
-        let d = make_obj(4);
+        let mut l1 = SinglyLinkedList::new(RcObjAdapter1::new());
+        let mut l2 = SinglyLinkedList::new(RcObjAdapter2::new());
+        let a = make_rc_obj(1);
+        let b = make_rc_obj(2);
+        let c = make_rc_obj(3);
+        let d = make_rc_obj(4);
         l1.cursor_mut().insert_after(d.clone());
         l1.cursor_mut().insert_after(c.clone());
         l1.cursor_mut().insert_after(b.clone());
@@ -1490,29 +1611,39 @@ mod tests {
     }
 
     #[test]
-    fn test_fast_clear() {
-        let mut l = SinglyLinkedList::new(ObjAdapter1::new());
-        let a = make_obj(1);
-        let b = make_obj(2);
-        let c = make_obj(3);
+    fn test_fast_clear_force_unlink() {
+        let mut l = SinglyLinkedList::new(UnsafeRefObjAdapter1::new());
+        let a = UnsafeRef::from_box(Box::new(make_obj(1)));
+        let b = UnsafeRef::from_box(Box::new(make_obj(2)));
+        let c = UnsafeRef::from_box(Box::new(make_obj(3)));
         l.cursor_mut().insert_after(a.clone());
         l.cursor_mut().insert_after(b.clone());
         l.cursor_mut().insert_after(c.clone());
 
         l.fast_clear();
         assert!(l.is_empty());
-        assert!(a.link1.is_linked());
-        assert!(b.link1.is_linked());
-        assert!(c.link1.is_linked());
+
         unsafe {
+            assert!(a.link1.is_linked());
+            assert!(b.link1.is_linked());
+            assert!(c.link1.is_linked());
+
             a.link1.force_unlink();
             b.link1.force_unlink();
             c.link1.force_unlink();
+
+            assert!(l.is_empty());
+
+            assert!(!a.link1.is_linked());
+            assert!(!b.link1.is_linked());
+            assert!(!c.link1.is_linked());
+        }
+
+        unsafe {
+            UnsafeRef::into_box(a);
+            UnsafeRef::into_box(b);
+            UnsafeRef::into_box(c);
         }
-        assert!(l.is_empty());
-        assert!(!a.link1.is_linked());
-        assert!(!b.link1.is_linked());
-        assert!(!c.link1.is_linked());
     }
 
     #[test]
diff --git a/src/xor_linked_list.rs b/src/xor_linked_list.rs
index d5c2ca3..4b8bd28 100644
--- a/src/xor_linked_list.rs
+++ b/src/xor_linked_list.rs
@@ -19,8 +19,10 @@ use core::sync::atomic::{AtomicUsize, Ordering};
 use crate::link_ops::{self, DefaultLinkOps};
 use crate::pointer_ops::PointerOps;
 use crate::singly_linked_list::SinglyLinkedListOps;
-use crate::unchecked_option::UncheckedOptionExt;
 use crate::Adapter;
+// Necessary for Rust 1.56 compatability
+#[allow(unused_imports)]
+use crate::unchecked_option::UncheckedOptionExt;
 
 // =============================================================================
 // XorLinkedListOps
@@ -466,7 +468,7 @@ unsafe fn link_between<T: XorLinkedListOps>(
 }
 
 // =============================================================================
-// Cursor, CursorMut
+// Cursor, CursorMut, CursorOwning
 // =============================================================================
 
 /// A cursor which provides read-only access to a `XorLinkedList`.
@@ -525,7 +527,7 @@ where
     where
         <A::PointerOps as PointerOps>::Pointer: Clone,
     {
-        let raw_pointer = self.get()? as *const <A::PointerOps as PointerOps>::Value;
+        let raw_pointer = unsafe { self.list.adapter.get_value(self.current?) };
         Some(unsafe {
             crate::pointer_ops::clone_pointer_from_raw(self.list.adapter.pointer_ops(), raw_pointer)
         })
@@ -1082,6 +1084,72 @@ where
     }
 }
 
+/// A cursor with ownership over the `XorLinkedList` it points into.
+pub struct CursorOwning<A: Adapter>
+where
+    A::LinkOps: XorLinkedListOps,
+{
+    current: Option<<A::LinkOps as link_ops::LinkOps>::LinkPtr>,
+    prev: Option<<A::LinkOps as link_ops::LinkOps>::LinkPtr>,
+    next: Option<<A::LinkOps as link_ops::LinkOps>::LinkPtr>,
+    list: XorLinkedList<A>,
+}
+
+impl<A: Adapter> CursorOwning<A>
+where
+    A::LinkOps: XorLinkedListOps,
+{
+    /// Consumes self and returns the inner `XorLinkedList`.
+    #[inline]
+    pub fn into_inner(self) -> XorLinkedList<A> {
+        self.list
+    }
+
+    /// Returns a read-only cursor pointing to the current element.
+    ///
+    /// The lifetime of the returned `Cursor` is bound to that of the
+    /// `CursorOwning`, which means it cannot outlive the `CursorOwning` and that the
+    /// `CursorOwning` is frozen for the lifetime of the `Cursor`.
+    ///
+    /// Mutations of the returned cursor are _not_ reflected in the original.
+    #[inline]
+    pub fn as_cursor(&self) -> Cursor<'_, A> {
+        Cursor {
+            current: self.current,
+            prev: self.prev,
+            next: self.next,
+            list: &self.list,
+        }
+    }
+
+    /// Perform action with mutable reference to the cursor.
+    ///
+    /// All mutations of the cursor are reflected in the original.
+    #[inline]
+    pub fn with_cursor_mut<T>(&mut self, f: impl FnOnce(&mut CursorMut<'_, A>) -> T) -> T {
+        let mut cursor = CursorMut {
+            current: self.current,
+            prev: self.prev,
+            next: self.next,
+            list: &mut self.list,
+        };
+
+        let ret = f(&mut cursor);
+
+        self.current = cursor.current;
+        self.prev = cursor.prev;
+        self.next = cursor.next;
+
+        ret
+    }
+}
+unsafe impl<A: Adapter> Send for CursorOwning<A>
+where
+    XorLinkedList<A>: Send,
+    A::LinkOps: XorLinkedListOps,
+{
+}
+
 // =============================================================================
 // XorLinkedList
 // =============================================================================
@@ -1178,6 +1246,17 @@ where
         }
     }
 
+    /// Returns a null `CursorOwning` for this list.
+    #[inline]
+    pub fn cursor_owning(self) -> CursorOwning<A> {
+        CursorOwning {
+            current: None,
+            prev: self.tail,
+            next: self.head,
+            list: self,
+        }
+    }
+
     /// Creates a `Cursor` from a pointer to an element and a pointer to the previous element.
     ///
     /// # Safety
@@ -1234,6 +1313,34 @@ where
         }
     }
 
+    /// Creates a `CursorOwning` from a pointer to an element and a pointer to the previous element.
+    ///
+    /// # Safety
+    ///
+    /// `ptr` must be a pointer to an object that is part of this list.
+    /// `prev` must be a pointer to an object that is the previous object in this list (null for the head)
+    #[inline]
+    pub unsafe fn cursor_owning_from_ptr_and_prev(
+        self,
+        ptr: *const <A::PointerOps as PointerOps>::Value,
+        prev: *const <A::PointerOps as PointerOps>::Value,
+    ) -> CursorOwning<A> {
+        let current = self.adapter.get_link(ptr);
+        let prev = if !prev.is_null() {
+            Some(self.adapter.get_link(prev))
+        } else {
+            None
+        };
+        let next = self.adapter.link_ops().next(current, prev);
+
+        CursorOwning {
+            current: Some(current),
+            prev,
+            next,
+            list: self,
+        }
+    }
+
     /// Creates a `Cursor` from a pointer to an element and a pointer to the next element.
     ///
     /// # Safety
@@ -1290,6 +1397,34 @@ where
         }
     }
 
+    /// Creates a `CursorOwning` from a pointer to an element and a pointer to the next element.
+    ///
+    /// # Safety
+    ///
+    /// `ptr` must be a pointer to an object that is part of this list.
+    /// `next` must be a pointer to an object that is the next object in this list (null for the tail)
+    #[inline]
+    pub unsafe fn cursor_owning_from_ptr_and_next(
+        self,
+        ptr: *const <A::PointerOps as PointerOps>::Value,
+        next: *const <A::PointerOps as PointerOps>::Value,
+    ) -> CursorOwning<A> {
+        let current = self.adapter.get_link(ptr);
+        let next = if !next.is_null() {
+            Some(self.adapter.get_link(next))
+        } else {
+            None
+        };
+        let prev = self.adapter.link_ops().prev(current, next);
+
+        CursorOwning {
+            current: Some(current),
+            prev,
+            next,
+            list: self,
+        }
+    }
+
     /// Returns a `Cursor` pointing to the first element of the list. If the
     /// list is empty then a null cursor is returned.
     #[inline]
@@ -1308,6 +1443,15 @@ where
         cursor
     }
 
+    /// Returns a `CursorOwning` pointing to the first element of the list. If the
+    /// the list is empty then a null cursor is returned.
+    #[inline]
+    pub fn front_owning(self) -> CursorOwning<A> {
+        let mut cursor = self.cursor_owning();
+        cursor.with_cursor_mut(|c| c.move_next());
+        cursor
+    }
+
     /// Returns a `Cursor` pointing to the last element of the list. If the list
     /// is empty then a null cursor is returned.
     #[inline]
@@ -1326,6 +1470,15 @@ where
         cursor
     }
 
+    /// Returns a `CursorOwning` pointing to the last element of the list. If the
+    /// list is empty then a null cursor is returned.
+    #[inline]
+    pub fn back_owning(self) -> CursorOwning<A> {
+        let mut cursor = self.cursor_owning();
+        cursor.with_cursor_mut(|c| c.move_prev());
+        cursor
+    }
+
     /// Gets an iterator over the objects in the `XorLinkedList`.
     #[inline]
     pub fn iter(&self) -> Iter<'_, A> {
@@ -1616,7 +1769,9 @@ where
 
 #[cfg(test)]
 mod tests {
-    use super::{Link, XorLinkedList};
+    use crate::UnsafeRef;
+
+    use super::{CursorOwning, Link, XorLinkedList};
     use core::cell::Cell;
     use core::ptr;
     use std::boxed::Box;
@@ -1635,24 +1790,29 @@ mod tests {
             write!(f, "{}", self.value)
         }
     }
-    intrusive_adapter!(ObjAdapter1 = Rc<Obj>: Obj { link1: Link });
-    intrusive_adapter!(ObjAdapter2 = Rc<Obj>: Obj { link2: Link });
+    intrusive_adapter!(RcObjAdapter1 = Rc<Obj>: Obj { link1: Link });
+    intrusive_adapter!(RcObjAdapter2 = Rc<Obj>: Obj { link2: Link });
+    intrusive_adapter!(UnsafeRefObjAdapter1 = UnsafeRef<Obj>: Obj { link1: Link });
 
-    fn make_obj(value: u32) -> Rc<Obj> {
-        Rc::new(Obj {
+    fn make_rc_obj(value: u32) -> Rc<Obj> {
+        Rc::new(make_obj(value))
+    }
+
+    fn make_obj(value: u32) -> Obj {
+        Obj {
             link1: Link::new(),
             link2: Link::default(),
             value,
-        })
+        }
     }
 
     #[test]
     fn test_link() {
-        let a = make_obj(1);
+        let a = make_rc_obj(1);
         assert!(!a.link1.is_linked());
         assert!(!a.link2.is_linked());
 
-        let mut b = XorLinkedList::<ObjAdapter1>::default();
+        let mut b = XorLinkedList::<RcObjAdapter1>::default();
         assert!(b.is_empty());
 
         b.cursor_mut().insert_after(a.clone());
@@ -1673,11 +1833,11 @@ mod tests {
 
     #[test]
     fn test_cursor() {
-        let a = make_obj(1);
-        let b = make_obj(2);
-        let c = make_obj(3);
+        let a = make_rc_obj(1);
+        let b = make_rc_obj(2);
+        let c = make_rc_obj(3);
 
-        let mut l = XorLinkedList::new(ObjAdapter1::new());
+        let mut l = XorLinkedList::new(RcObjAdapter1::new());
         let mut cur = l.cursor_mut();
         assert!(cur.is_null());
         assert!(cur.get().is_none());
@@ -1755,12 +1915,38 @@ mod tests {
     }
 
     #[test]
+    fn test_cursor_owning() {
+        struct Container {
+            cur: CursorOwning<RcObjAdapter1>,
+        }
+
+        let mut l = XorLinkedList::new(RcObjAdapter1::new());
+        l.push_back(make_rc_obj(1));
+        l.push_back(make_rc_obj(2));
+        l.push_back(make_rc_obj(3));
+        l.push_back(make_rc_obj(4));
+        let mut con = Container {
+            cur: l.cursor_owning(),
+        };
+        assert!(con.cur.as_cursor().is_null());
+
+        con.cur = con.cur.into_inner().front_owning();
+        assert_eq!(con.cur.as_cursor().get().unwrap().value, 1);
+
+        con.cur.with_cursor_mut(|c| c.move_next());
+        assert_eq!(con.cur.as_cursor().get().unwrap().value, 2);
+
+        con.cur = con.cur.into_inner().back_owning();
+        assert_eq!(con.cur.as_cursor().get().unwrap().value, 4);
+    }
+
+    #[test]
     fn test_push_pop() {
-        let a = make_obj(1);
-        let b = make_obj(2);
-        let c = make_obj(3);
+        let a = make_rc_obj(1);
+        let b = make_rc_obj(2);
+        let c = make_rc_obj(3);
 
-        let mut l = XorLinkedList::new(ObjAdapter1::new());
+        let mut l = XorLinkedList::new(RcObjAdapter1::new());
         l.push_front(a);
         assert_eq!(l.iter().map(|x| x.value).collect::<Vec<_>>(), [1]);
         l.push_front(b);
@@ -1781,14 +1967,14 @@ mod tests {
 
     #[test]
     fn test_split_splice() {
-        let mut l1 = XorLinkedList::new(ObjAdapter1::new());
-        let mut l2 = XorLinkedList::new(ObjAdapter1::new());
-        let mut l3 = XorLinkedList::new(ObjAdapter1::new());
-
-        let a = make_obj(1);
-        let b = make_obj(2);
-        let c = make_obj(3);
-        let d = make_obj(4);
+        let mut l1 = XorLinkedList::new(RcObjAdapter1::new());
+        let mut l2 = XorLinkedList::new(RcObjAdapter1::new());
+        let mut l3 = XorLinkedList::new(RcObjAdapter1::new());
+
+        let a = make_rc_obj(1);
+        let b = make_rc_obj(2);
+        let c = make_rc_obj(3);
+        let d = make_rc_obj(4);
         l1.cursor_mut().insert_before(a);
         l1.cursor_mut().insert_before(b);
         l1.cursor_mut().insert_before(c);
@@ -1872,11 +2058,11 @@ mod tests {
 
     #[test]
     fn test_iter() {
-        let mut l = XorLinkedList::new(ObjAdapter1::new());
-        let a = make_obj(1);
-        let b = make_obj(2);
-        let c = make_obj(3);
-        let d = make_obj(4);
+        let mut l = XorLinkedList::new(RcObjAdapter1::new());
+        let a = make_rc_obj(1);
+        let b = make_rc_obj(2);
+        let c = make_rc_obj(3);
+        let d = make_rc_obj(4);
         l.cursor_mut().insert_before(a.clone());
         l.cursor_mut().insert_before(b.clone());
         l.cursor_mut().insert_before(c.clone());
@@ -1979,12 +2165,12 @@ mod tests {
 
     #[test]
     fn test_multi_list() {
-        let mut l1 = XorLinkedList::new(ObjAdapter1::new());
-        let mut l2 = XorLinkedList::new(ObjAdapter2::new());
-        let a = make_obj(1);
-        let b = make_obj(2);
-        let c = make_obj(3);
-        let d = make_obj(4);
+        let mut l1 = XorLinkedList::new(RcObjAdapter1::new());
+        let mut l2 = XorLinkedList::new(RcObjAdapter2::new());
+        let a = make_rc_obj(1);
+        let b = make_rc_obj(2);
+        let c = make_rc_obj(3);
+        let d = make_rc_obj(4);
         l1.cursor_mut().insert_before(a.clone());
         l1.cursor_mut().insert_before(b.clone());
         l1.cursor_mut().insert_before(c.clone());
@@ -1998,46 +2184,56 @@ mod tests {
     }
 
     #[test]
-    fn test_force_unlink() {
-        let mut l = XorLinkedList::new(ObjAdapter1::new());
-        let a = make_obj(1);
-        let b = make_obj(2);
-        let c = make_obj(3);
+    fn test_fast_clear_force_unlink() {
+        let mut l = XorLinkedList::new(UnsafeRefObjAdapter1::new());
+        let a = UnsafeRef::from_box(Box::new(make_obj(1)));
+        let b = UnsafeRef::from_box(Box::new(make_obj(2)));
+        let c = UnsafeRef::from_box(Box::new(make_obj(3)));
         l.cursor_mut().insert_before(a.clone());
         l.cursor_mut().insert_before(b.clone());
         l.cursor_mut().insert_before(c.clone());
 
         l.fast_clear();
         assert!(l.is_empty());
-        assert!(a.link1.is_linked());
-        assert!(b.link1.is_linked());
-        assert!(c.link1.is_linked());
+
         unsafe {
+            assert!(a.link1.is_linked());
+            assert!(b.link1.is_linked());
+            assert!(c.link1.is_linked());
+
             a.link1.force_unlink();
             b.link1.force_unlink();
             c.link1.force_unlink();
+
+            assert!(l.is_empty());
+
+            assert!(!a.link1.is_linked());
+            assert!(!b.link1.is_linked());
+            assert!(!c.link1.is_linked());
+        }
+
+        unsafe {
+            UnsafeRef::into_box(a);
+            UnsafeRef::into_box(b);
+            UnsafeRef::into_box(c);
         }
-        assert!(l.is_empty());
-        assert!(!a.link1.is_linked());
-        assert!(!b.link1.is_linked());
-        assert!(!c.link1.is_linked());
     }
 
     #[test]
     fn test_reverse() {
-        let mut l = XorLinkedList::new(ObjAdapter1::new());
+        let mut l = XorLinkedList::new(RcObjAdapter1::new());
 
-        l.push_back(make_obj(1));
-        l.push_back(make_obj(2));
-        l.push_back(make_obj(3));
-        l.push_back(make_obj(4));
+        l.push_back(make_rc_obj(1));
+        l.push_back(make_rc_obj(2));
+        l.push_back(make_rc_obj(3));
+        l.push_back(make_rc_obj(4));
         assert_eq!(l.iter().map(|x| x.value).collect::<Vec<_>>(), [1, 2, 3, 4]);
 
         l.reverse();
         assert_eq!(l.iter().map(|x| x.value).collect::<Vec<_>>(), [4, 3, 2, 1]);
 
-        l.push_back(make_obj(5));
-        l.push_back(make_obj(6));
+        l.push_back(make_rc_obj(5));
+        l.push_back(make_rc_obj(6));
         assert_eq!(
             l.iter().map(|x| x.value).collect::<Vec<_>>(),
             [4, 3, 2, 1, 5, 6]