Struct zone_alloc::KeyedArena

pub struct KeyedArena<K, T> { /* private fields */ }

The same as Arena<T>, but each inserted value is internally mapped to a custom key for retrieving the value later.

Similar to crate::Registry, except a KeyMap is used internally, which requires key hashing or ordering. Hashing is used by default. In no_std builds, ordering is used.

Implementations

impl<K, T> KeyedArena<K, T>

where K: Key,

pub fn new() -> Self

Creates a new keyed arena.

pub fn with_capacity(size: usize) -> Self

Creates a new keyed arena with the given capacity.

pub fn len(&self) -> usize

Returns the number of elements owned by the arena.

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

Inserts a new value in the arena, returning a mutable reference to that vaue.

Returns None if a value already exists for key.

pub fn reserve(&self, additional: usize)

Ensures there is enough continuous space for at least additional values.

pub fn iter_mut(&mut self) -> IterMut<'_, K, T>

Returns an iterator that provides mutable access to all elements in the arena.

There is no guaranteed order of entries.

KeyedArenas only allow mutable iteration because the entire arena must be borrowed for the duration of the iteration. The mutable borrow to call this method allows Rust’s borrow checker to enforce this rule.

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

Returns an iterator over all keys in the arena.

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

Returns an iterator over mutable references to all elements in the arena.

pub fn get_mut<R>(&self, key: &R) -> Option<&mut T>

where K: Borrow<R>, R: Key + ?Sized,

Returns a mutable reference to a value previously inserted into the arena.

pub fn get<R>(&self, key: &R) -> Option<&T>

where K: Borrow<R>, R: Key + ?Sized,

Returns a reference to a value previously inserted into the arena.

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

where K: Borrow<R>, R: Key + ?Sized,

Checks if the arena contains a value for the given key.