diff --git a/alloc/src/collections/linked_list.rs b/alloc/src/collections/linked_list.rs index 052edf453..2c26f9e03 100644 --- a/alloc/src/collections/linked_list.rs +++ b/alloc/src/collections/linked_list.rs @@ -18,7 +18,7 @@ use core::hash::{Hash, Hasher}; use core::iter::FusedIterator; use core::marker::PhantomData; use core::mem; -use core::ptr::{NonNull, Unique}; +use core::ptr::NonNull; use super::SpecExtend; use crate::alloc::{Allocator, Global}; @@ -168,15 +168,16 @@ impl LinkedList { /// Adds the given node to the front of the list. /// /// # Safety - /// `node` must point to a valid node that was boxed using the list's allocator. + /// `node` must point to a valid node that was boxed and leaked using the list's allocator. + /// This method takes ownership of the node, so the pointer should not be used again. #[inline] - unsafe fn push_front_node(&mut self, node: Unique>) { + unsafe fn push_front_node(&mut self, node: NonNull>) { // This method takes care not to create mutable references to whole nodes, // to maintain validity of aliasing pointers into `element`. unsafe { (*node.as_ptr()).next = self.head; (*node.as_ptr()).prev = None; - let node = Some(NonNull::from(node)); + let node = Some(node); match self.head { None => self.tail = node, @@ -212,15 +213,16 @@ impl LinkedList { /// Adds the given node to the back of the list. /// /// # Safety - /// `node` must point to a valid node that was boxed using the list's allocator. + /// `node` must point to a valid node that was boxed and leaked using the list's allocator. + /// This method takes ownership of the node, so the pointer should not be used again. #[inline] - unsafe fn push_back_node(&mut self, node: Unique>) { + unsafe fn push_back_node(&mut self, node: NonNull>) { // This method takes care not to create mutable references to whole nodes, // to maintain validity of aliasing pointers into `element`. unsafe { (*node.as_ptr()).next = None; (*node.as_ptr()).prev = self.tail; - let node = Some(NonNull::from(node)); + let node = Some(node); match self.tail { None => self.head = node, @@ -842,8 +844,8 @@ impl LinkedList { #[stable(feature = "rust1", since = "1.0.0")] pub fn push_front(&mut self, elt: T) { let node = Box::new_in(Node::new(elt), &self.alloc); - let node_ptr = Unique::from(Box::leak(node)); - // SAFETY: node_ptr is a unique pointer to a node we boxed with self.alloc + let node_ptr = NonNull::from(Box::leak(node)); + // SAFETY: node_ptr is a unique pointer to a node we boxed with self.alloc and leaked unsafe { self.push_front_node(node_ptr); } @@ -890,8 +892,8 @@ impl LinkedList { #[stable(feature = "rust1", since = "1.0.0")] pub fn push_back(&mut self, elt: T) { let node = Box::new_in(Node::new(elt), &self.alloc); - let node_ptr = Unique::from(Box::leak(node)); - // SAFETY: node_ptr is a unique pointer to a node we boxed with self.alloc + let node_ptr = NonNull::from(Box::leak(node)); + // SAFETY: node_ptr is a unique pointer to a node we boxed with self.alloc and leaked unsafe { self.push_back_node(node_ptr); }