pub struct LinkedList<T, A: Allocator = Global> { /* private fields */ }
Expand description
A doubly-linked list with owned nodes.
The LinkedList
allows pushing and popping elements at either end
in constant time.
A LinkedList
with a known list of items can be initialized from an array:
NOTE: It is almost always better to use Vec
or VecDeque
because
array-based containers are generally faster,
more memory efficient, and make better use of CPU cache.
Implementations§
source§impl<T> LinkedList<T>
impl<T> LinkedList<T>
1.0.0 · sourcepub fn append(&mut self, other: &mut Self)
pub fn append(&mut self, other: &mut Self)
Moves all elements from other
to the end of the list.
This reuses all the nodes from other
and moves them into self
. After
this operation, other
becomes empty.
This operation should compute in O(1) time and O(1) memory.
§Examples
use std::collections::LinkedList;
let mut list1 = LinkedList::new();
list1.push_back('a');
let mut list2 = LinkedList::new();
list2.push_back('b');
list2.push_back('c');
list1.append(&mut list2);
let mut iter = list1.iter();
assert_eq!(iter.next(), Some(&'a'));
assert_eq!(iter.next(), Some(&'b'));
assert_eq!(iter.next(), Some(&'c'));
assert!(iter.next().is_none());
assert!(list2.is_empty());
source§impl<T, A: Allocator> LinkedList<T, A>
impl<T, A: Allocator> LinkedList<T, A>
sourcepub const fn new_in(alloc: A) -> Self
🔬This is a nightly-only experimental API. (allocator_api
#32838)
pub const fn new_in(alloc: A) -> Self
allocator_api
#32838)Constructs an empty LinkedList<T, A>
.
§Examples
1.0.0 · sourcepub fn iter(&self) -> Iter<'_, T> ⓘ
pub fn iter(&self) -> Iter<'_, T> ⓘ
Provides a forward iterator.
§Examples
use std::collections::LinkedList;
let mut list: LinkedList<u32> = LinkedList::new();
list.push_back(0);
list.push_back(1);
list.push_back(2);
let mut iter = list.iter();
assert_eq!(iter.next(), Some(&0));
assert_eq!(iter.next(), Some(&1));
assert_eq!(iter.next(), Some(&2));
assert_eq!(iter.next(), None);
1.0.0 · sourcepub fn iter_mut(&mut self) -> IterMut<'_, T> ⓘ
pub fn iter_mut(&mut self) -> IterMut<'_, T> ⓘ
Provides a forward iterator with mutable references.
§Examples
use std::collections::LinkedList;
let mut list: LinkedList<u32> = LinkedList::new();
list.push_back(0);
list.push_back(1);
list.push_back(2);
for element in list.iter_mut() {
*element += 10;
}
let mut iter = list.iter();
assert_eq!(iter.next(), Some(&10));
assert_eq!(iter.next(), Some(&11));
assert_eq!(iter.next(), Some(&12));
assert_eq!(iter.next(), None);
sourcepub fn cursor_front(&self) -> Cursor<'_, T, A>
🔬This is a nightly-only experimental API. (linked_list_cursors
#58533)
pub fn cursor_front(&self) -> Cursor<'_, T, A>
linked_list_cursors
#58533)Provides a cursor at the front element.
The cursor is pointing to the “ghost” non-element if the list is empty.
sourcepub fn cursor_front_mut(&mut self) -> CursorMut<'_, T, A>
🔬This is a nightly-only experimental API. (linked_list_cursors
#58533)
pub fn cursor_front_mut(&mut self) -> CursorMut<'_, T, A>
linked_list_cursors
#58533)Provides a cursor with editing operations at the front element.
The cursor is pointing to the “ghost” non-element if the list is empty.
sourcepub fn cursor_back(&self) -> Cursor<'_, T, A>
🔬This is a nightly-only experimental API. (linked_list_cursors
#58533)
pub fn cursor_back(&self) -> Cursor<'_, T, A>
linked_list_cursors
#58533)Provides a cursor at the back element.
The cursor is pointing to the “ghost” non-element if the list is empty.
sourcepub fn cursor_back_mut(&mut self) -> CursorMut<'_, T, A>
🔬This is a nightly-only experimental API. (linked_list_cursors
#58533)
pub fn cursor_back_mut(&mut self) -> CursorMut<'_, T, A>
linked_list_cursors
#58533)Provides a cursor with editing operations at the back element.
The cursor is pointing to the “ghost” non-element if the list is empty.
1.0.0 · sourcepub fn is_empty(&self) -> bool
pub fn is_empty(&self) -> bool
1.0.0 · sourcepub fn len(&self) -> usize
pub fn len(&self) -> usize
1.0.0 · sourcepub fn clear(&mut self)
pub fn clear(&mut self)
1.12.0 · sourcepub fn contains(&self, x: &T) -> boolwhere
T: PartialEq<T>,
pub fn contains(&self, x: &T) -> boolwhere
T: PartialEq<T>,
Returns true
if the LinkedList
contains an element equal to the
given value.
This operation should compute linearly in O(n) time.
§Examples
1.0.0 · sourcepub fn front(&self) -> Option<&T>
pub fn front(&self) -> Option<&T>
Provides a reference to the front element, or None
if the list is
empty.
This operation should compute in O(1) time.
§Examples
1.0.0 · sourcepub fn front_mut(&mut self) -> Option<&mut T>
pub fn front_mut(&mut self) -> Option<&mut T>
Provides a mutable reference to the front element, or None
if the list
is empty.
This operation should compute in O(1) time.
§Examples
1.0.0 · sourcepub fn back(&self) -> Option<&T>
pub fn back(&self) -> Option<&T>
Provides a reference to the back element, or None
if the list is
empty.
This operation should compute in O(1) time.
§Examples
1.0.0 · sourcepub fn back_mut(&mut self) -> Option<&mut T>
pub fn back_mut(&mut self) -> Option<&mut T>
Provides a mutable reference to the back element, or None
if the list
is empty.
This operation should compute in O(1) time.
§Examples
1.0.0 · sourcepub fn push_front(&mut self, elt: T)
pub fn push_front(&mut self, elt: T)
1.0.0 · sourcepub fn pop_front(&mut self) -> Option<T>
pub fn pop_front(&mut self) -> Option<T>
Removes the first element and returns it, or None
if the list is
empty.
This operation should compute in O(1) time.
§Examples
1.0.0 · sourcepub fn push_back(&mut self, elt: T)
pub fn push_back(&mut self, elt: T)
1.0.0 · sourcepub fn pop_back(&mut self) -> Option<T>
pub fn pop_back(&mut self) -> Option<T>
Removes the last element from a list and returns it, or None
if
it is empty.
This operation should compute in O(1) time.
§Examples
1.0.0 · sourcepub fn split_off(&mut self, at: usize) -> LinkedList<T, A>where
A: Clone,
pub fn split_off(&mut self, at: usize) -> LinkedList<T, A>where
A: Clone,
sourcepub fn remove(&mut self, at: usize) -> T
🔬This is a nightly-only experimental API. (linked_list_remove
#69210)
pub fn remove(&mut self, at: usize) -> T
linked_list_remove
#69210)sourcepub fn retain<F>(&mut self, f: F)
🔬This is a nightly-only experimental API. (linked_list_retain
#114135)
pub fn retain<F>(&mut self, f: F)
linked_list_retain
#114135)Retains only the elements specified by the predicate.
In other words, remove all elements e
for which f(&e)
returns false.
This method operates in place, visiting each element exactly once in the
original order, and preserves the order of the retained elements.
§Examples
#![feature(linked_list_retain)]
use std::collections::LinkedList;
let mut d = LinkedList::new();
d.push_front(1);
d.push_front(2);
d.push_front(3);
d.retain(|&x| x % 2 == 0);
assert_eq!(d.pop_front(), Some(2));
assert_eq!(d.pop_front(), None);
Because the elements are visited exactly once in the original order, external state may be used to decide which elements to keep.
#![feature(linked_list_retain)]
use std::collections::LinkedList;
let mut d = LinkedList::new();
d.push_front(1);
d.push_front(2);
d.push_front(3);
let keep = [false, true, false];
let mut iter = keep.iter();
d.retain(|_| *iter.next().unwrap());
assert_eq!(d.pop_front(), Some(2));
assert_eq!(d.pop_front(), None);
sourcepub fn retain_mut<F>(&mut self, f: F)
🔬This is a nightly-only experimental API. (linked_list_retain
#114135)
pub fn retain_mut<F>(&mut self, f: F)
linked_list_retain
#114135)Retains only the elements specified by the predicate.
In other words, remove all elements e
for which f(&e)
returns false.
This method operates in place, visiting each element exactly once in the
original order, and preserves the order of the retained elements.
§Examples
sourcepub fn extract_if<F>(&mut self, filter: F) -> ExtractIf<'_, T, F, A> ⓘ
🔬This is a nightly-only experimental API. (extract_if
#43244)
pub fn extract_if<F>(&mut self, filter: F) -> ExtractIf<'_, T, F, A> ⓘ
extract_if
#43244)Creates an iterator which uses a closure to determine if an element should be removed.
If the closure returns true, then the element is removed and yielded. If the closure returns false, the element will remain in the list and will not be yielded by the iterator.
If the returned ExtractIf
is not exhausted, e.g. because it is dropped without iterating
or the iteration short-circuits, then the remaining elements will be retained.
Use extract_if().for_each(drop)
if you do not need the returned iterator.
Note that extract_if
lets you mutate every element in the filter closure, regardless of
whether you choose to keep or remove it.
§Examples
Splitting a list into evens and odds, reusing the original list:
#![feature(extract_if)]
use std::collections::LinkedList;
let mut numbers: LinkedList<u32> = LinkedList::new();
numbers.extend(&[1, 2, 3, 4, 5, 6, 8, 9, 11, 13, 14, 15]);
let evens = numbers.extract_if(|x| *x % 2 == 0).collect::<LinkedList<_>>();
let odds = numbers;
assert_eq!(evens.into_iter().collect::<Vec<_>>(), vec![2, 4, 6, 8, 14]);
assert_eq!(odds.into_iter().collect::<Vec<_>>(), vec![1, 3, 5, 9, 11, 13, 15]);
Trait Implementations§
1.36.0 · source§impl<T: Clone, A: Allocator + Clone> Clone for LinkedList<T, A>
impl<T: Clone, A: Allocator + Clone> Clone for LinkedList<T, A>
source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
Overwrites the contents of self
with a clone of the contents of source
.
This method is preferred over simply assigning source.clone()
to self
,
as it avoids reallocation of the nodes of the linked list. Additionally,
if the element type T
overrides clone_from()
, this will reuse the
resources of self
’s elements as well.
1.36.0 · source§impl<T> Default for LinkedList<T>
impl<T> Default for LinkedList<T>
1.36.0 · source§impl<T, A: Allocator> Drop for LinkedList<T, A>
impl<T, A: Allocator> Drop for LinkedList<T, A>
1.36.0 · source§impl<'a, T: 'a + Copy, A: Allocator> Extend<&'a T> for LinkedList<T, A>
impl<'a, T: 'a + Copy, A: Allocator> Extend<&'a T> for LinkedList<T, A>
1.36.0 · source§impl<T, A: Allocator> Extend<T> for LinkedList<T, A>
impl<T, A: Allocator> Extend<T> for LinkedList<T, A>
source§fn extend<I: IntoIterator<Item = T>>(&mut self, iter: I)
fn extend<I: IntoIterator<Item = T>>(&mut self, iter: I)
source§fn extend_one(&mut self, elem: T)
fn extend_one(&mut self, elem: T)
extend_one
#72631)