Doubly-linked list/Element insertion: Difference between revisions

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 head = DListNode.from_array([:a, :b])
 head.insert_after(:a, :c)</lang>
+=={{header|Rust}}==
+This expands upon the implementation defined in [[Doubly-linked list/Element definition#Rust]] and consists of the relevant lines from the LinkedList implementation in the Rust standard library.
+<lang rust>struct Node<T> {
+    next: Link<T>,
+    prev: Rawlink<Node<T>>,
+    value: T,
+}
+impl<T> Node<T> {
+    fn new(v: T) -> Node<T> {
+        Node {value: v, next: None, prev: Rawlink::none()}
+    }
+}
+impl<T> Rawlink<T> {
+    fn none() -> Self {
+        Rawlink {p: ptr::null_mut()}
+    }
+    fn some(n: &mut T) -> Rawlink<T> {
+        Rawlink{p: n}
+    }
+}
+impl<'a, T> From<&'a mut Link<T>> for Rawlink<Node<T>> {
+    fn from(node: &'a mut Link<T>) -> Self {
+        match node.as_mut() {
+            None => Rawlink::none(),
+            Some(ptr) => Rawlink::some(ptr)
+        }
+    }
+}
+fn link_no_prev<T>(mut next: Box<Node<T>>) -> Link<T> {
+    next.prev = Rawlink::none();
+    Some(next)
+}
+impl<T> LinkedList<T> {
+    #[inline]
+    fn push_front_node(&mut self, mut new_head: Box<Node<T>>) {
+        match self.list_head {
+            None => {
+                self.list_head = link_no_prev(new_head);
+                self.list_tail = Rawlink::from(&mut self.list_head);
+            }
+            Some(ref mut head) => {
+                new_head.prev = Rawlink::none();
+                head.prev = Rawlink::some(&mut *new_head);
+                mem::swap(head, &mut new_head);
+                head.next = Some(new_head);
+            }
+        }
+        self.length += 1;
+    }
+    pub fn push_front(&mut self, elt: T) {
+        self.push_front_node(Box::new(Node::new(elt)));
+    }
+}</lang>
 =={{header|Tcl}}==