Struct IndexMap

pub struct IndexMap<K, V> { /* private fields */ }

A hash table where the iteration order of the key-value pairs is independent of the hash values of the keys.

Provides an API compatible with both IndexMap and a custom implementation based on BTreeMap.

Implementations

impl<K, V> IndexMap<K, V>

pub fn clear(&mut self)

Clears the IndexMap, removing all elements.

pub fn len(&self) -> usize

Returns the number of elements in the IndexMap.

pub fn is_empty(&self) -> bool

Returns true if the IndexMap contains no elements.

pub fn iter(&self) -> Iter<'_, K, V>

Returns an iterator that yields the items in the IndexMap.

pub fn iter_mut(&mut self) -> IterMut<'_, K, V>

Returns an iterator that yields the mutable items in the IndexMap.

pub fn keys(&self) -> Keys<'_, K, V>

Returns an iterator that yields the keys in the IndexMap.

pub fn values(&self) -> Values<'_, K, V>

Returns an iterator that yields the values in the IndexMap.

pub fn values_mut(&mut self) -> ValuesMut<'_, K, V>

Returns a mutable iterator that yields the values in the IndexMap.

pub fn get_index(&self, index: usize) -> Option<(&K, &V)>

Returns the key-value entry at the given index if any.

pub fn get_index_mut(&mut self, index: usize) -> Option<(&K, &mut V)>

Returns the mutable key-value entry at the given index if any.

impl<K, V> IndexMap<K, V>

where K: Hash + Eq + Ord + Clone,

pub fn reserve(&mut self, additional: usize)

Reserves capacity for at least additional more elements to be inserted in the IndexMap.

pub fn contains_key<Q>(&self, key: &Q) -> bool

where K: Borrow<Q>, Q: Hash + Eq + Ord + ?Sized,

Returns true if key is contains in the IndexMap.

pub fn get<Q>(&self, key: &Q) -> Option<&V>

where K: Borrow<Q>, Q: Hash + Eq + Ord + ?Sized,

Returns a reference to the value corresponding to the key.

pub fn get_key_value<Q>(&self, key: &Q) -> Option<(&K, &V)>

where K: Borrow<Q>, Q: Hash + Eq + Ord + ?Sized,

Return references to the key-value pair stored for key, if it is present, else None.

pub fn get_full<Q>(&self, key: &Q) -> Option<(usize, &K, &V)>

where K: Borrow<Q> + Ord, Q: Hash + Eq + Ord + ?Sized,

Returns the key-value pair corresponding to the supplied key as well as the unique index of the returned key-value pair.

The supplied key may be any borrowed form of the map’s key type, but the ordering on the borrowed form must match the ordering on the key type.

pub fn get_mut<Q>(&mut self, key: &Q) -> Option<&mut V>

where K: Borrow<Q>, Q: Hash + Eq + Ord + ?Sized,

Returns a mutable reference to the value corresponding to the key.

pub fn insert(&mut self, key: K, value: V) -> Option<V>

Inserts a key-value pair into the IndexMap.

If the map did not have this key present, None is returned.

If the map did have this key present, the value is updated, and the old value is returned. The key is not updated, though; this matters for types that can be == without being identical.

pub fn swap_remove<Q>(&mut self, key: &Q) -> Option<V>

where K: Borrow<Q>, Q: Hash + Eq + Ord + ?Sized,

Remove the key-value pair equivalent to key and return its value.

Like Vec::swap_remove, the pair is removed by swapping it with the last element of the map and popping it off. This perturbs the position of what used to be the last element!

Return None if key is not in map.

pub fn swap_remove_entry<Q>(&mut self, key: &Q) -> Option<(K, V)>

where K: Borrow<Q>, Q: Hash + Eq + Ord + ?Sized,

Remove and return the key-value pair equivalent to key.

Like Vec::swap_remove, the pair is removed by swapping it with the last element of the map and popping it off. This perturbs the position of what used to be the last element!

Return None if key is not in map.

pub fn entry(&mut self, key: K) -> Entry<'_, K, V>

Gets the given key’s corresponding entry in the IndexMap for in-place manipulation.

Trait Implementations

impl<K, V> Clone for IndexMap<K, V>

where K: Clone, V: Clone,

fn clone(&self) -> IndexMap<K, V>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<K, V> Debug for IndexMap<K, V>

where K: Debug, V: Debug,

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl<K, V> Default for IndexMap<K, V>

fn default() -> IndexMap<K, V>

Returns the “default value” for a type.

impl<K, V> Extend<(K, V)> for IndexMap<K, V>

where K: Eq + Hash + Ord + Clone,

fn extend<Iter>(&mut self, iter: Iter)

where Iter: IntoIterator<Item = (K, V)>,

Extends a collection with the contents of an iterator.

fn extend_one(&mut self, item: A)

🔬This is a nightly-only experimental API. (extend_one)

Extends a collection with exactly one element.

fn extend_reserve(&mut self, additional: usize)

🔬This is a nightly-only experimental API. (extend_one)

Reserves capacity in a collection for the given number of additional elements.

impl<K, V> FromIterator<(K, V)> for IndexMap<K, V>

where K: Hash + Ord + Eq + Clone,

fn from_iter<I>(iter: I) -> IndexMap<K, V>

where I: IntoIterator<Item = (K, V)>,

Creates a value from an iterator.

impl<K, Q, V> Index<&Q> for IndexMap<K, V>

where K: Borrow<Q> + Hash + Eq + Ord, Q: Hash + Eq + Ord + ?Sized,

type Output = V

The returned type after indexing.

fn index(&self, key: &Q) -> &V

Performs the indexing (container[index]) operation.

impl<K, V> Index<usize> for IndexMap<K, V>

where K: Hash + Eq + Ord,

type Output = V

The returned type after indexing.

fn index(&self, key: usize) -> &V

Performs the indexing (container[index]) operation.

impl<'a, K, V> IntoIterator for &'a IndexMap<K, V>

type Item = (&'a K, &'a V)

The type of the elements being iterated over.

type IntoIter = Iter<'a, K, V>

Which kind of iterator are we turning this into?

fn into_iter(self) -> <&'a IndexMap<K, V> as IntoIterator>::IntoIter

Creates an iterator from a value.

impl<'a, K, V> IntoIterator for &'a mut IndexMap<K, V>

type Item = (&'a K, &'a mut V)

The type of the elements being iterated over.

type IntoIter = IterMut<'a, K, V>

Which kind of iterator are we turning this into?

fn into_iter(self) -> <&'a mut IndexMap<K, V> as IntoIterator>::IntoIter

Creates an iterator from a value.

impl<K, V> IntoIterator for IndexMap<K, V>

type Item = (K, V)

The type of the elements being iterated over.

type IntoIter = IntoIter<K, V>

Which kind of iterator are we turning this into?

fn into_iter(self) -> <IndexMap<K, V> as IntoIterator>::IntoIter

Creates an iterator from a value.

impl<K, V> PartialEq for IndexMap<K, V>

where K: PartialEq + Hash + Ord, V: PartialEq,

fn eq(&self, other: &IndexMap<K, V>) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &IndexMap<K, V>) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<K, V> Eq for IndexMap<K, V>

where K: Eq + Hash + Ord, V: Eq,