Struct SmallMap 

pub struct SmallMap<K, V, const N: usize>(/* private fields */);

A hash map, with a fast non-cryptographic hasher and deterministic iteration order, optimized for the common case of very few entries.

Up to N entries are stored inline, in a flat, linearly-scanned array, with no heap allocation and no hashing. Once an insert grows the map past N entries, it transparently and permanently promotes itself to an IMap

Implementations

impl<K, V, const N: usize> SmallMap<K, V, N>

pub fn new() -> SmallMap<K, V, N>

Creates an empty SmallMap. Does not allocate until it grows past N entries.

pub fn is_inline(&self) -> bool

Returns true if this map has not (yet) grown past N entries, i.e., is still using inline, non-heap-allocated storage.

pub fn len(&self) -> usize

Returns the number of elements in the map.

pub fn is_empty(&self) -> bool

Returns true if the map contains no elements.

pub fn clear(&mut self)

Clears the map, removing all key-value pairs. A previously promoted map stays promoted; see the SmallMap documentation.

pub fn retain<F>(&mut self, f: F)

where F: FnMut(&K, &mut V) -> bool,

Retains only the elements specified by the predicate.

In other words, remove all pairs (k, v) such that f(&k, &mut v) returns false.

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

Returns an iterator over the map’s key-value pairs.

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

Returns a mutable iterator over the map’s key-value pairs.

pub fn keys(&self) -> impl Iterator<Item = &K>

Returns an iterator over the map’s keys.

pub fn values(&self) -> impl Iterator<Item = &V>

Returns an iterator over the map’s values.

pub fn values_mut(&mut self) -> impl Iterator<Item = &mut V>

Returns a mutable iterator over the map’s values.

impl<K, V, const N: usize> SmallMap<K, V, N>

where K: Hash + Eq,

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

Inserts a key-value pair into the map.

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

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

Returns a reference to the value corresponding to the key.

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

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

Returns a mutable 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 + ?Sized,

Returns the key-value pair corresponding to the supplied key.

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

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

Returns true if the map contains a value for the specified key.

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

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

Removes a key from the map, returning the value at the key if the key was previously in the map.

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

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

Trait Implementations

impl<K, V, const N: usize> Clone for SmallMap<K, V, N>

where K: Clone, V: Clone,

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

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<K, V, const N: usize> Debug for SmallMap<K, V, N>

where K: Debug, V: Debug,

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

Formats the value using the given formatter.

impl<K, V, const N: usize> Default for SmallMap<K, V, N>

fn default() -> SmallMap<K, V, N>

Returns the “default value” for a type.

impl<K, V, const N: usize> Eq for SmallMap<K, V, N>

where K: Hash + Eq, V: Eq,

impl<K, V, const N: usize> Extend<(K, V)> for SmallMap<K, V, N>

where K: Hash + Eq,

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

where I: 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 From<SmallMap<Identifier, Box<dyn Attribute>, 1>> for AttributeDict

fn from(value: SmallMap<Identifier, Box<dyn Attribute>, 1>) -> AttributeDict

Converts to this type from the input type.

impl<K, V, const N: usize> FromIterator<(K, V)> for SmallMap<K, V, N>

where K: Hash + Eq,

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

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

Creates a value from an iterator.

impl<K, V, const N: usize> IntoIterator for SmallMap<K, V, N>

type Item = (K, V)

The type of the elements being iterated over.

type IntoIter = MapIntoIter<K, V, N>

Which kind of iterator are we turning this into?

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

Creates an iterator from a value.

impl<'a, K, V, const N: usize> IntoIterator for &'a SmallMap<K, V, N>

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

The type of the elements being iterated over.

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

Which kind of iterator are we turning this into?

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

Creates an iterator from a value.

impl<K, V, const N: usize> PartialEq for SmallMap<K, V, N>

where K: Hash + Eq, V: PartialEq,

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

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.