1199 lines
33 KiB
Rust
1199 lines
33 KiB
Rust
// Copyright 2012-2015 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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//! A doubly-linked list with owned nodes.
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//!
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//! The `LinkedList` allows pushing and popping elements at either end and is thus
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//! efficiently usable as a double-ended queue.
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// LinkedList is constructed like a singly-linked list over the field `next`.
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// including the last link being None; each Node owns its `next` field.
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//
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// Backlinks over LinkedList::prev are raw pointers that form a full chain in
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// the reverse direction.
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#![stable(feature = "rust1", since = "1.0.0")]
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use core::prelude::*;
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use alloc::boxed::Box;
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use core::cmp::Ordering;
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use core::fmt;
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use core::hash::{Hasher, Hash};
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use core::iter::{self, FromIterator};
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use core::mem;
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use core::ptr;
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/// A doubly-linked list.
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#[stable(feature = "rust1", since = "1.0.0")]
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pub struct LinkedList<T> {
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length: usize,
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list_head: Link<T>,
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list_tail: Rawlink<Node<T>>,
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}
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type Link<T> = Option<Box<Node<T>>>;
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struct Rawlink<T> {
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p: *mut T,
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}
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impl<T> Copy for Rawlink<T> {}
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unsafe impl<T:Send> Send for Rawlink<T> {}
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unsafe impl<T:Sync> Sync for Rawlink<T> {}
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struct Node<T> {
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next: Link<T>,
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prev: Rawlink<Node<T>>,
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value: T,
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}
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/// An iterator over references to the items of a `LinkedList`.
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#[stable(feature = "rust1", since = "1.0.0")]
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pub struct Iter<'a, T:'a> {
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head: &'a Link<T>,
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tail: Rawlink<Node<T>>,
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nelem: usize,
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}
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// FIXME #19839: deriving is too aggressive on the bounds (T doesn't need to be Clone).
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#[stable(feature = "rust1", since = "1.0.0")]
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impl<'a, T> Clone for Iter<'a, T> {
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fn clone(&self) -> Iter<'a, T> {
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Iter {
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head: self.head.clone(),
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tail: self.tail,
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nelem: self.nelem,
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}
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}
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}
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/// An iterator over mutable references to the items of a `LinkedList`.
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#[stable(feature = "rust1", since = "1.0.0")]
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pub struct IterMut<'a, T:'a> {
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list: &'a mut LinkedList<T>,
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head: Rawlink<Node<T>>,
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tail: Rawlink<Node<T>>,
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nelem: usize,
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}
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/// An iterator over mutable references to the items of a `LinkedList`.
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#[derive(Clone)]
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#[stable(feature = "rust1", since = "1.0.0")]
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pub struct IntoIter<T> {
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list: LinkedList<T>
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}
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/// Rawlink is a type like Option<T> but for holding a raw pointer
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impl<T> Rawlink<T> {
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/// Like Option::None for Rawlink
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fn none() -> Rawlink<T> {
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Rawlink{p: ptr::null_mut()}
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}
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/// Like Option::Some for Rawlink
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fn some(n: &mut T) -> Rawlink<T> {
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Rawlink{p: n}
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}
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/// Convert the `Rawlink` into an Option value
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///
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/// **unsafe** because:
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///
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/// - Dereference of raw pointer.
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/// - Returns reference of arbitrary lifetime.
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unsafe fn resolve<'a>(&self) -> Option<&'a T> {
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self.p.as_ref()
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}
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/// Convert the `Rawlink` into an Option value
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///
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/// **unsafe** because:
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///
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/// - Dereference of raw pointer.
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/// - Returns reference of arbitrary lifetime.
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unsafe fn resolve_mut<'a>(&mut self) -> Option<&'a mut T> {
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self.p.as_mut()
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}
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/// Return the `Rawlink` and replace with `Rawlink::none()`
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fn take(&mut self) -> Rawlink<T> {
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mem::replace(self, Rawlink::none())
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}
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}
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impl<'a, T> From<&'a mut Link<T>> for Rawlink<Node<T>> {
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fn from(node: &'a mut Link<T>) -> Self {
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match node.as_mut() {
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None => Rawlink::none(),
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Some(ptr) => Rawlink::some(ptr),
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}
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}
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}
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impl<T> Clone for Rawlink<T> {
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#[inline]
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fn clone(&self) -> Rawlink<T> {
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Rawlink{p: self.p}
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}
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}
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impl<T> Node<T> {
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fn new(v: T) -> Node<T> {
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Node{value: v, next: None, prev: Rawlink::none()}
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}
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/// Update the `prev` link on `next`, then set self's next pointer.
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///
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/// `self.next` should be `None` when you call this
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/// (otherwise a Node is probably being dropped by mistake).
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fn set_next(&mut self, mut next: Box<Node<T>>) {
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debug_assert!(self.next.is_none());
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next.prev = Rawlink::some(self);
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self.next = Some(next);
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}
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}
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/// Clear the .prev field on `next`, then return `Some(next)`
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fn link_no_prev<T>(mut next: Box<Node<T>>) -> Link<T> {
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next.prev = Rawlink::none();
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Some(next)
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}
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// private methods
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impl<T> LinkedList<T> {
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/// Add a Node first in the list
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#[inline]
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fn push_front_node(&mut self, mut new_head: Box<Node<T>>) {
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match self.list_head {
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None => {
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self.list_head = link_no_prev(new_head);
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self.list_tail = Rawlink::from(&mut self.list_head);
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}
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Some(ref mut head) => {
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new_head.prev = Rawlink::none();
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head.prev = Rawlink::some(&mut *new_head);
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mem::swap(head, &mut new_head);
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head.next = Some(new_head);
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}
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}
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self.length += 1;
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}
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/// Remove the first Node and return it, or None if the list is empty
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#[inline]
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fn pop_front_node(&mut self) -> Option<Box<Node<T>>> {
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self.list_head.take().map(|mut front_node| {
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self.length -= 1;
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match front_node.next.take() {
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Some(node) => self.list_head = link_no_prev(node),
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None => self.list_tail = Rawlink::none()
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}
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front_node
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})
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}
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/// Add a Node last in the list
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#[inline]
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fn push_back_node(&mut self, new_tail: Box<Node<T>>) {
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match unsafe { self.list_tail.resolve_mut() } {
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None => return self.push_front_node(new_tail),
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Some(tail) => {
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tail.set_next(new_tail);
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self.list_tail = Rawlink::from(&mut tail.next);
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}
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}
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self.length += 1;
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}
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/// Remove the last Node and return it, or None if the list is empty
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#[inline]
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fn pop_back_node(&mut self) -> Option<Box<Node<T>>> {
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unsafe {
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self.list_tail.resolve_mut().and_then(|tail| {
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self.length -= 1;
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self.list_tail = tail.prev;
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match tail.prev.resolve_mut() {
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None => self.list_head.take(),
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Some(tail_prev) => tail_prev.next.take()
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}
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})
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}
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}
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}
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#[stable(feature = "rust1", since = "1.0.0")]
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impl<T> Default for LinkedList<T> {
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#[inline]
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#[stable(feature = "rust1", since = "1.0.0")]
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fn default() -> LinkedList<T> { LinkedList::new() }
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}
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impl<T> LinkedList<T> {
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/// Creates an empty `LinkedList`.
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#[inline]
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#[stable(feature = "rust1", since = "1.0.0")]
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pub fn new() -> LinkedList<T> {
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LinkedList{list_head: None, list_tail: Rawlink::none(), length: 0}
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}
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/// Moves all elements from `other` to the end of the list.
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///
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/// This reuses all the nodes from `other` and moves them into `self`. After
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/// this operation, `other` becomes empty.
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///
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/// This operation should compute in O(1) time and O(1) memory.
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///
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/// # Examples
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///
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/// ```
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/// use std::collections::LinkedList;
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///
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/// let mut a = LinkedList::new();
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/// let mut b = LinkedList::new();
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/// a.push_back(1);
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/// a.push_back(2);
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/// b.push_back(3);
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/// b.push_back(4);
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///
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/// a.append(&mut b);
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///
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/// for e in &a {
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/// println!("{}", e); // prints 1, then 2, then 3, then 4
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/// }
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/// println!("{}", b.len()); // prints 0
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/// ```
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#[stable(feature = "rust1", since = "1.0.0")]
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pub fn append(&mut self, other: &mut LinkedList<T>) {
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match unsafe { self.list_tail.resolve_mut() } {
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None => {
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self.length = other.length;
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self.list_head = other.list_head.take();
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self.list_tail = other.list_tail.take();
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},
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Some(tail) => {
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// Carefully empty `other`.
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let o_tail = other.list_tail.take();
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let o_length = other.length;
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match other.list_head.take() {
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None => return,
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Some(node) => {
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tail.set_next(node);
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self.list_tail = o_tail;
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self.length += o_length;
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}
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}
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}
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}
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other.length = 0;
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}
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/// Provides a forward iterator.
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#[inline]
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#[stable(feature = "rust1", since = "1.0.0")]
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pub fn iter(&self) -> Iter<T> {
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Iter{nelem: self.len(), head: &self.list_head, tail: self.list_tail}
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}
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/// Provides a forward iterator with mutable references.
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#[inline]
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#[stable(feature = "rust1", since = "1.0.0")]
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pub fn iter_mut(&mut self) -> IterMut<T> {
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IterMut {
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nelem: self.len(),
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head: Rawlink::from(&mut self.list_head),
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tail: self.list_tail,
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list: self
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}
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}
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/// Returns `true` if the `LinkedList` is empty.
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///
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/// This operation should compute in O(1) time.
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///
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/// # Examples
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///
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/// ```
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/// use std::collections::LinkedList;
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///
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/// let mut dl = LinkedList::new();
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/// assert!(dl.is_empty());
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///
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/// dl.push_front("foo");
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/// assert!(!dl.is_empty());
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/// ```
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#[inline]
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#[stable(feature = "rust1", since = "1.0.0")]
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pub fn is_empty(&self) -> bool {
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self.list_head.is_none()
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}
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/// Returns the length of the `LinkedList`.
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///
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/// This operation should compute in O(1) time.
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///
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/// # Examples
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///
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/// ```
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/// use std::collections::LinkedList;
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///
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/// let mut dl = LinkedList::new();
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///
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/// dl.push_front(2);
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/// assert_eq!(dl.len(), 1);
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///
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/// dl.push_front(1);
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/// assert_eq!(dl.len(), 2);
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///
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/// dl.push_back(3);
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/// assert_eq!(dl.len(), 3);
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///
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/// ```
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#[inline]
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#[stable(feature = "rust1", since = "1.0.0")]
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pub fn len(&self) -> usize {
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self.length
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}
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/// Removes all elements from the `LinkedList`.
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///
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/// This operation should compute in O(n) time.
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///
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/// # Examples
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///
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/// ```
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/// use std::collections::LinkedList;
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///
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/// let mut dl = LinkedList::new();
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///
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/// dl.push_front(2);
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/// dl.push_front(1);
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/// assert_eq!(dl.len(), 2);
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/// assert_eq!(dl.front(), Some(&1));
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///
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/// dl.clear();
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/// assert_eq!(dl.len(), 0);
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/// assert_eq!(dl.front(), None);
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///
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/// ```
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#[inline]
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#[stable(feature = "rust1", since = "1.0.0")]
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pub fn clear(&mut self) {
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*self = LinkedList::new()
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}
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/// Provides a reference to the front element, or `None` if the list is
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/// empty.
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///
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/// # Examples
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///
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/// ```
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/// use std::collections::LinkedList;
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///
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/// let mut dl = LinkedList::new();
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/// assert_eq!(dl.front(), None);
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///
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/// dl.push_front(1);
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/// assert_eq!(dl.front(), Some(&1));
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///
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/// ```
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#[inline]
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#[stable(feature = "rust1", since = "1.0.0")]
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pub fn front(&self) -> Option<&T> {
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self.list_head.as_ref().map(|head| &head.value)
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}
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/// Provides a mutable reference to the front element, or `None` if the list
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/// is empty.
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///
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/// # Examples
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///
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/// ```
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/// use std::collections::LinkedList;
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///
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/// let mut dl = LinkedList::new();
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/// assert_eq!(dl.front(), None);
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///
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/// dl.push_front(1);
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/// assert_eq!(dl.front(), Some(&1));
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///
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/// match dl.front_mut() {
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/// None => {},
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/// Some(x) => *x = 5,
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/// }
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/// assert_eq!(dl.front(), Some(&5));
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///
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/// ```
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#[inline]
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#[stable(feature = "rust1", since = "1.0.0")]
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pub fn front_mut(&mut self) -> Option<&mut T> {
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self.list_head.as_mut().map(|head| &mut head.value)
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}
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/// Provides a reference to the back element, or `None` if the list is
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/// empty.
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///
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/// # Examples
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///
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/// ```
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/// use std::collections::LinkedList;
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///
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/// let mut dl = LinkedList::new();
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/// assert_eq!(dl.back(), None);
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///
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/// dl.push_back(1);
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/// assert_eq!(dl.back(), Some(&1));
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///
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/// ```
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#[inline]
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#[stable(feature = "rust1", since = "1.0.0")]
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pub fn back(&self) -> Option<&T> {
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unsafe {
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self.list_tail.resolve().map(|tail| &tail.value)
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}
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}
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/// Provides a mutable reference to the back element, or `None` if the list
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/// is empty.
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///
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/// # Examples
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///
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/// ```
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/// use std::collections::LinkedList;
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///
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/// let mut dl = LinkedList::new();
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/// assert_eq!(dl.back(), None);
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///
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/// dl.push_back(1);
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/// assert_eq!(dl.back(), Some(&1));
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///
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/// match dl.back_mut() {
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/// None => {},
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/// Some(x) => *x = 5,
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/// }
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/// assert_eq!(dl.back(), Some(&5));
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///
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/// ```
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#[inline]
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#[stable(feature = "rust1", since = "1.0.0")]
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pub fn back_mut(&mut self) -> Option<&mut T> {
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unsafe {
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self.list_tail.resolve_mut().map(|tail| &mut tail.value)
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}
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}
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|
|
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/// Adds an element first in the list.
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///
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/// This operation should compute in O(1) time.
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///
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/// # Examples
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///
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/// ```
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/// use std::collections::LinkedList;
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///
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/// let mut dl = LinkedList::new();
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///
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/// dl.push_front(2);
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/// assert_eq!(dl.front().unwrap(), &2);
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///
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/// dl.push_front(1);
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/// assert_eq!(dl.front().unwrap(), &1);
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///
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/// ```
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#[stable(feature = "rust1", since = "1.0.0")]
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pub fn push_front(&mut self, elt: T) {
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self.push_front_node(box Node::new(elt))
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}
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|
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/// Removes the first element and returns it, or `None` if the list is
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/// empty.
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///
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|
/// This operation should compute in O(1) time.
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///
|
|
/// # Examples
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|
///
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/// ```
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/// use std::collections::LinkedList;
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///
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/// let mut d = LinkedList::new();
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/// assert_eq!(d.pop_front(), None);
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///
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/// d.push_front(1);
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/// d.push_front(3);
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/// assert_eq!(d.pop_front(), Some(3));
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/// assert_eq!(d.pop_front(), Some(1));
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/// assert_eq!(d.pop_front(), None);
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///
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/// ```
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///
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#[stable(feature = "rust1", since = "1.0.0")]
|
|
pub fn pop_front(&mut self) -> Option<T> {
|
|
self.pop_front_node().map(|box Node{value, ..}| value)
|
|
}
|
|
|
|
/// Appends an element to the back of a list
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// use std::collections::LinkedList;
|
|
///
|
|
/// let mut d = LinkedList::new();
|
|
/// d.push_back(1);
|
|
/// d.push_back(3);
|
|
/// assert_eq!(3, *d.back().unwrap());
|
|
/// ```
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
pub fn push_back(&mut self, elt: T) {
|
|
self.push_back_node(box Node::new(elt))
|
|
}
|
|
|
|
/// Removes the last element from a list and returns it, or `None` if
|
|
/// it is empty.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// use std::collections::LinkedList;
|
|
///
|
|
/// let mut d = LinkedList::new();
|
|
/// assert_eq!(d.pop_back(), None);
|
|
/// d.push_back(1);
|
|
/// d.push_back(3);
|
|
/// assert_eq!(d.pop_back(), Some(3));
|
|
/// ```
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
pub fn pop_back(&mut self) -> Option<T> {
|
|
self.pop_back_node().map(|box Node{value, ..}| value)
|
|
}
|
|
|
|
/// Splits the list into two at the given index. Returns everything after the given index,
|
|
/// including the index.
|
|
///
|
|
/// # Panics
|
|
///
|
|
/// Panics if `at > len`.
|
|
///
|
|
/// This operation should compute in O(n) time.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// use std::collections::LinkedList;
|
|
///
|
|
/// let mut d = LinkedList::new();
|
|
///
|
|
/// d.push_front(1);
|
|
/// d.push_front(2);
|
|
/// d.push_front(3);
|
|
///
|
|
/// let mut splitted = d.split_off(2);
|
|
///
|
|
/// assert_eq!(splitted.pop_front(), Some(1));
|
|
/// assert_eq!(splitted.pop_front(), None);
|
|
/// ```
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
pub fn split_off(&mut self, at: usize) -> LinkedList<T> {
|
|
let len = self.len();
|
|
assert!(at <= len, "Cannot split off at a nonexistent index");
|
|
if at == 0 {
|
|
return mem::replace(self, LinkedList::new());
|
|
} else if at == len {
|
|
return LinkedList::new();
|
|
}
|
|
|
|
// Below, we iterate towards the `i-1`th node, either from the start or the end,
|
|
// depending on which would be faster.
|
|
let mut split_node = if at - 1 <= len - 1 - (at - 1) {
|
|
let mut iter = self.iter_mut();
|
|
// instead of skipping using .skip() (which creates a new struct),
|
|
// we skip manually so we can access the head field without
|
|
// depending on implementation details of Skip
|
|
for _ in 0..at - 1 {
|
|
iter.next();
|
|
}
|
|
iter.head
|
|
} else {
|
|
// better off starting from the end
|
|
let mut iter = self.iter_mut();
|
|
for _ in 0..len - 1 - (at - 1) {
|
|
iter.next_back();
|
|
}
|
|
iter.tail
|
|
};
|
|
|
|
// The split node is the new tail node of the first part and owns
|
|
// the head of the second part.
|
|
let mut second_part_head;
|
|
|
|
unsafe {
|
|
second_part_head = split_node.resolve_mut().unwrap().next.take();
|
|
match second_part_head {
|
|
None => {}
|
|
Some(ref mut head) => head.prev = Rawlink::none(),
|
|
}
|
|
}
|
|
|
|
let second_part = LinkedList {
|
|
list_head: second_part_head,
|
|
list_tail: self.list_tail,
|
|
length: len - at
|
|
};
|
|
|
|
// Fix the tail ptr of the first part
|
|
self.list_tail = split_node;
|
|
self.length = at;
|
|
|
|
second_part
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<T> Drop for LinkedList<T> {
|
|
fn drop(&mut self) {
|
|
// Dissolve the linked_list in a loop.
|
|
// Just dropping the list_head can lead to stack exhaustion
|
|
// when length is >> 1_000_000
|
|
while let Some(mut head_) = self.list_head.take() {
|
|
self.list_head = head_.next.take();
|
|
}
|
|
self.length = 0;
|
|
self.list_tail = Rawlink::none();
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<'a, A> Iterator for Iter<'a, A> {
|
|
type Item = &'a A;
|
|
|
|
#[inline]
|
|
fn next(&mut self) -> Option<&'a A> {
|
|
if self.nelem == 0 {
|
|
return None;
|
|
}
|
|
self.head.as_ref().map(|head| {
|
|
self.nelem -= 1;
|
|
self.head = &head.next;
|
|
&head.value
|
|
})
|
|
}
|
|
|
|
#[inline]
|
|
fn size_hint(&self) -> (usize, Option<usize>) {
|
|
(self.nelem, Some(self.nelem))
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<'a, A> DoubleEndedIterator for Iter<'a, A> {
|
|
#[inline]
|
|
fn next_back(&mut self) -> Option<&'a A> {
|
|
if self.nelem == 0 {
|
|
return None;
|
|
}
|
|
unsafe {
|
|
self.tail.resolve().map(|prev| {
|
|
self.nelem -= 1;
|
|
self.tail = prev.prev;
|
|
&prev.value
|
|
})
|
|
}
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<'a, A> ExactSizeIterator for Iter<'a, A> {}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<'a, A> Iterator for IterMut<'a, A> {
|
|
type Item = &'a mut A;
|
|
#[inline]
|
|
fn next(&mut self) -> Option<&'a mut A> {
|
|
if self.nelem == 0 {
|
|
return None;
|
|
}
|
|
unsafe {
|
|
self.head.resolve_mut().map(|next| {
|
|
self.nelem -= 1;
|
|
self.head = Rawlink::from(&mut next.next);
|
|
&mut next.value
|
|
})
|
|
}
|
|
}
|
|
|
|
#[inline]
|
|
fn size_hint(&self) -> (usize, Option<usize>) {
|
|
(self.nelem, Some(self.nelem))
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<'a, A> DoubleEndedIterator for IterMut<'a, A> {
|
|
#[inline]
|
|
fn next_back(&mut self) -> Option<&'a mut A> {
|
|
if self.nelem == 0 {
|
|
return None;
|
|
}
|
|
unsafe {
|
|
self.tail.resolve_mut().map(|prev| {
|
|
self.nelem -= 1;
|
|
self.tail = prev.prev;
|
|
&mut prev.value
|
|
})
|
|
}
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<'a, A> ExactSizeIterator for IterMut<'a, A> {}
|
|
|
|
// private methods for IterMut
|
|
impl<'a, A> IterMut<'a, A> {
|
|
fn insert_next_node(&mut self, mut ins_node: Box<Node<A>>) {
|
|
// Insert before `self.head` so that it is between the
|
|
// previously yielded element and self.head.
|
|
//
|
|
// The inserted node will not appear in further iteration.
|
|
match unsafe { self.head.resolve_mut() } {
|
|
None => { self.list.push_back_node(ins_node); }
|
|
Some(node) => {
|
|
let prev_node = match unsafe { node.prev.resolve_mut() } {
|
|
None => return self.list.push_front_node(ins_node),
|
|
Some(prev) => prev,
|
|
};
|
|
let node_own = prev_node.next.take().unwrap();
|
|
ins_node.set_next(node_own);
|
|
prev_node.set_next(ins_node);
|
|
self.list.length += 1;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<'a, A> IterMut<'a, A> {
|
|
/// Inserts `elt` just after the element most recently returned by `.next()`.
|
|
/// The inserted element does not appear in the iteration.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// # #![feature(linked_list_extras)]
|
|
/// use std::collections::LinkedList;
|
|
///
|
|
/// let mut list: LinkedList<_> = vec![1, 3, 4].into_iter().collect();
|
|
///
|
|
/// {
|
|
/// let mut it = list.iter_mut();
|
|
/// assert_eq!(it.next().unwrap(), &1);
|
|
/// // insert `2` after `1`
|
|
/// it.insert_next(2);
|
|
/// }
|
|
/// {
|
|
/// let vec: Vec<_> = list.into_iter().collect();
|
|
/// assert_eq!(vec, [1, 2, 3, 4]);
|
|
/// }
|
|
/// ```
|
|
#[inline]
|
|
#[unstable(feature = "linked_list_extras",
|
|
reason = "this is probably better handled by a cursor type -- we'll see")]
|
|
pub fn insert_next(&mut self, elt: A) {
|
|
self.insert_next_node(box Node::new(elt))
|
|
}
|
|
|
|
/// Provides a reference to the next element, without changing the iterator.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// # #![feature(linked_list_extras)]
|
|
/// use std::collections::LinkedList;
|
|
///
|
|
/// let mut list: LinkedList<_> = vec![1, 2, 3].into_iter().collect();
|
|
///
|
|
/// let mut it = list.iter_mut();
|
|
/// assert_eq!(it.next().unwrap(), &1);
|
|
/// assert_eq!(it.peek_next().unwrap(), &2);
|
|
/// // We just peeked at 2, so it was not consumed from the iterator.
|
|
/// assert_eq!(it.next().unwrap(), &2);
|
|
/// ```
|
|
#[inline]
|
|
#[unstable(feature = "linked_list_extras",
|
|
reason = "this is probably better handled by a cursor type -- we'll see")]
|
|
pub fn peek_next(&mut self) -> Option<&mut A> {
|
|
if self.nelem == 0 {
|
|
return None
|
|
}
|
|
unsafe {
|
|
self.head.resolve_mut().map(|head| &mut head.value)
|
|
}
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<A> Iterator for IntoIter<A> {
|
|
type Item = A;
|
|
|
|
#[inline]
|
|
fn next(&mut self) -> Option<A> { self.list.pop_front() }
|
|
|
|
#[inline]
|
|
fn size_hint(&self) -> (usize, Option<usize>) {
|
|
(self.list.length, Some(self.list.length))
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<A> DoubleEndedIterator for IntoIter<A> {
|
|
#[inline]
|
|
fn next_back(&mut self) -> Option<A> { self.list.pop_back() }
|
|
}
|
|
|
|
impl<A> ExactSizeIterator for IntoIter<A> {}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<A> FromIterator<A> for LinkedList<A> {
|
|
fn from_iter<T: IntoIterator<Item=A>>(iter: T) -> LinkedList<A> {
|
|
let mut ret = LinkedList::new();
|
|
ret.extend(iter);
|
|
ret
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<T> IntoIterator for LinkedList<T> {
|
|
type Item = T;
|
|
type IntoIter = IntoIter<T>;
|
|
|
|
/// Consumes the list into an iterator yielding elements by value.
|
|
#[inline]
|
|
fn into_iter(self) -> IntoIter<T> {
|
|
IntoIter{list: self}
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<'a, T> IntoIterator for &'a LinkedList<T> {
|
|
type Item = &'a T;
|
|
type IntoIter = Iter<'a, T>;
|
|
|
|
fn into_iter(self) -> Iter<'a, T> {
|
|
self.iter()
|
|
}
|
|
}
|
|
|
|
impl<'a, T> IntoIterator for &'a mut LinkedList<T> {
|
|
type Item = &'a mut T;
|
|
type IntoIter = IterMut<'a, T>;
|
|
|
|
fn into_iter(mut self) -> IterMut<'a, T> {
|
|
self.iter_mut()
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<A> Extend<A> for LinkedList<A> {
|
|
fn extend<T: IntoIterator<Item=A>>(&mut self, iter: T) {
|
|
for elt in iter { self.push_back(elt); }
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "extend_ref", since = "1.2.0")]
|
|
impl<'a, T: 'a + Copy> Extend<&'a T> for LinkedList<T> {
|
|
fn extend<I: IntoIterator<Item=&'a T>>(&mut self, iter: I) {
|
|
self.extend(iter.into_iter().cloned());
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<A: PartialEq> PartialEq for LinkedList<A> {
|
|
fn eq(&self, other: &LinkedList<A>) -> bool {
|
|
self.len() == other.len() &&
|
|
iter::order::eq(self.iter(), other.iter())
|
|
}
|
|
|
|
fn ne(&self, other: &LinkedList<A>) -> bool {
|
|
self.len() != other.len() ||
|
|
iter::order::ne(self.iter(), other.iter())
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<A: Eq> Eq for LinkedList<A> {}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<A: PartialOrd> PartialOrd for LinkedList<A> {
|
|
fn partial_cmp(&self, other: &LinkedList<A>) -> Option<Ordering> {
|
|
iter::order::partial_cmp(self.iter(), other.iter())
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<A: Ord> Ord for LinkedList<A> {
|
|
#[inline]
|
|
fn cmp(&self, other: &LinkedList<A>) -> Ordering {
|
|
iter::order::cmp(self.iter(), other.iter())
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<A: Clone> Clone for LinkedList<A> {
|
|
fn clone(&self) -> LinkedList<A> {
|
|
self.iter().cloned().collect()
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<A: fmt::Debug> fmt::Debug for LinkedList<A> {
|
|
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
|
|
f.debug_list().entries(self.iter()).finish()
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<A: Hash> Hash for LinkedList<A> {
|
|
fn hash<H: Hasher>(&self, state: &mut H) {
|
|
self.len().hash(state);
|
|
for elt in self {
|
|
elt.hash(state);
|
|
}
|
|
}
|
|
}
|
|
|
|
#[cfg(test)]
|
|
mod tests {
|
|
use std::clone::Clone;
|
|
use std::iter::{Iterator, IntoIterator, Extend};
|
|
use std::option::Option::{Some, None, self};
|
|
use std::__rand::{thread_rng, Rng};
|
|
use std::thread;
|
|
use std::vec::Vec;
|
|
|
|
use super::{LinkedList, Node};
|
|
|
|
#[cfg(test)]
|
|
fn list_from<T: Clone>(v: &[T]) -> LinkedList<T> {
|
|
v.iter().cloned().collect()
|
|
}
|
|
|
|
pub fn check_links<T>(list: &LinkedList<T>) {
|
|
let mut len = 0;
|
|
let mut last_ptr: Option<&Node<T>> = None;
|
|
let mut node_ptr: &Node<T>;
|
|
match list.list_head {
|
|
None => { assert_eq!(0, list.length); return }
|
|
Some(ref node) => node_ptr = &**node,
|
|
}
|
|
loop {
|
|
match unsafe { (last_ptr, node_ptr.prev.resolve()) } {
|
|
(None , None ) => {}
|
|
(None , _ ) => panic!("prev link for list_head"),
|
|
(Some(p), Some(pptr)) => {
|
|
assert_eq!(p as *const Node<T>, pptr as *const Node<T>);
|
|
}
|
|
_ => panic!("prev link is none, not good"),
|
|
}
|
|
match node_ptr.next {
|
|
Some(ref next) => {
|
|
last_ptr = Some(node_ptr);
|
|
node_ptr = &**next;
|
|
len += 1;
|
|
}
|
|
None => {
|
|
len += 1;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
assert_eq!(len, list.length);
|
|
}
|
|
|
|
#[test]
|
|
fn test_append() {
|
|
// Empty to empty
|
|
{
|
|
let mut m = LinkedList::<i32>::new();
|
|
let mut n = LinkedList::new();
|
|
m.append(&mut n);
|
|
check_links(&m);
|
|
assert_eq!(m.len(), 0);
|
|
assert_eq!(n.len(), 0);
|
|
}
|
|
// Non-empty to empty
|
|
{
|
|
let mut m = LinkedList::new();
|
|
let mut n = LinkedList::new();
|
|
n.push_back(2);
|
|
m.append(&mut n);
|
|
check_links(&m);
|
|
assert_eq!(m.len(), 1);
|
|
assert_eq!(m.pop_back(), Some(2));
|
|
assert_eq!(n.len(), 0);
|
|
check_links(&m);
|
|
}
|
|
// Empty to non-empty
|
|
{
|
|
let mut m = LinkedList::new();
|
|
let mut n = LinkedList::new();
|
|
m.push_back(2);
|
|
m.append(&mut n);
|
|
check_links(&m);
|
|
assert_eq!(m.len(), 1);
|
|
assert_eq!(m.pop_back(), Some(2));
|
|
check_links(&m);
|
|
}
|
|
|
|
// Non-empty to non-empty
|
|
let v = vec![1,2,3,4,5];
|
|
let u = vec![9,8,1,2,3,4,5];
|
|
let mut m = list_from(&v);
|
|
let mut n = list_from(&u);
|
|
m.append(&mut n);
|
|
check_links(&m);
|
|
let mut sum = v;
|
|
sum.push_all(&u);
|
|
assert_eq!(sum.len(), m.len());
|
|
for elt in sum {
|
|
assert_eq!(m.pop_front(), Some(elt))
|
|
}
|
|
assert_eq!(n.len(), 0);
|
|
// let's make sure it's working properly, since we
|
|
// did some direct changes to private members
|
|
n.push_back(3);
|
|
assert_eq!(n.len(), 1);
|
|
assert_eq!(n.pop_front(), Some(3));
|
|
check_links(&n);
|
|
}
|
|
|
|
#[test]
|
|
fn test_insert_prev() {
|
|
let mut m = list_from(&[0,2,4,6,8]);
|
|
let len = m.len();
|
|
{
|
|
let mut it = m.iter_mut();
|
|
it.insert_next(-2);
|
|
loop {
|
|
match it.next() {
|
|
None => break,
|
|
Some(elt) => {
|
|
it.insert_next(*elt + 1);
|
|
match it.peek_next() {
|
|
Some(x) => assert_eq!(*x, *elt + 2),
|
|
None => assert_eq!(8, *elt),
|
|
}
|
|
}
|
|
}
|
|
}
|
|
it.insert_next(0);
|
|
it.insert_next(1);
|
|
}
|
|
check_links(&m);
|
|
assert_eq!(m.len(), 3 + len * 2);
|
|
assert_eq!(m.into_iter().collect::<Vec<_>>(), [-2,0,1,2,3,4,5,6,7,8,9,0,1]);
|
|
}
|
|
|
|
#[test]
|
|
fn test_send() {
|
|
let n = list_from(&[1,2,3]);
|
|
thread::spawn(move || {
|
|
check_links(&n);
|
|
let a: &[_] = &[&1,&2,&3];
|
|
assert_eq!(a, &n.iter().collect::<Vec<_>>()[..]);
|
|
}).join().ok().unwrap();
|
|
}
|
|
|
|
#[test]
|
|
fn test_fuzz() {
|
|
for _ in 0..25 {
|
|
fuzz_test(3);
|
|
fuzz_test(16);
|
|
fuzz_test(189);
|
|
}
|
|
}
|
|
|
|
#[test]
|
|
fn test_26021() {
|
|
use std::iter::ExactSizeIterator;
|
|
// There was a bug in split_off that failed to null out the RHS's head's prev ptr.
|
|
// This caused the RHS's dtor to walk up into the LHS at drop and delete all of
|
|
// its nodes.
|
|
//
|
|
// https://github.com/rust-lang/rust/issues/26021
|
|
let mut v1 = LinkedList::new();
|
|
v1.push_front(1u8);
|
|
v1.push_front(1u8);
|
|
v1.push_front(1u8);
|
|
v1.push_front(1u8);
|
|
let _ = v1.split_off(3); // Dropping this now should not cause laundry consumption
|
|
assert_eq!(v1.len(), 3);
|
|
|
|
assert_eq!(v1.iter().len(), 3);
|
|
assert_eq!(v1.iter().collect::<Vec<_>>().len(), 3);
|
|
}
|
|
|
|
#[test]
|
|
fn test_split_off() {
|
|
let mut v1 = LinkedList::new();
|
|
v1.push_front(1u8);
|
|
v1.push_front(1u8);
|
|
v1.push_front(1u8);
|
|
v1.push_front(1u8);
|
|
|
|
// test all splits
|
|
for ix in 0..1 + v1.len() {
|
|
let mut a = v1.clone();
|
|
let b = a.split_off(ix);
|
|
check_links(&a);
|
|
check_links(&b);
|
|
a.extend(b);
|
|
assert_eq!(v1, a);
|
|
}
|
|
}
|
|
|
|
|
|
#[cfg(test)]
|
|
fn fuzz_test(sz: i32) {
|
|
let mut m: LinkedList<_> = LinkedList::new();
|
|
let mut v = vec![];
|
|
for i in 0..sz {
|
|
check_links(&m);
|
|
let r: u8 = thread_rng().next_u32() as u8;
|
|
match r % 6 {
|
|
0 => {
|
|
m.pop_back();
|
|
v.pop();
|
|
}
|
|
1 => {
|
|
if !v.is_empty() {
|
|
m.pop_front();
|
|
v.remove(0);
|
|
}
|
|
}
|
|
2 | 4 => {
|
|
m.push_front(-i);
|
|
v.insert(0, -i);
|
|
}
|
|
3 | 5 | _ => {
|
|
m.push_back(i);
|
|
v.push(i);
|
|
}
|
|
}
|
|
}
|
|
|
|
check_links(&m);
|
|
|
|
let mut i = 0;
|
|
for (a, &b) in m.into_iter().zip(&v) {
|
|
i += 1;
|
|
assert_eq!(a, b);
|
|
}
|
|
assert_eq!(i, v.len());
|
|
}
|
|
}
|