Struct ArenaMap 

pub struct ArenaMap<T, V> { /* private fields */ }

A dense map from arena indices to values.

Backed by a Vec<Option<V>> aligned with an arena, allowing O(1) lookup by index.

Implementations

impl<T, V> ArenaMap<T, V>

pub fn new() -> Self

Create an empty ArenaMap.

pub fn insert(&mut self, idx: Idx<T>, value: V)

Insert a value for idx, growing the map if necessary.

pub fn get(&self, idx: Idx<T>) -> Option<&V>

Get a reference to the value for idx.

pub fn get_mut(&mut self, idx: Idx<T>) -> Option<&mut V>

Get a mutable reference to the value for idx.

pub fn remove(&mut self, idx: Idx<T>) -> Option<V>

Remove the value at idx.

pub fn contains(&self, idx: Idx<T>) -> bool

Check whether idx has a value.

pub fn count(&self) -> usize

Number of non-empty entries.

pub fn iter(&self) -> impl Iterator<Item = (Idx<T>, &V)>

Iterate over all (index, value) pairs.

Trait Implementations

impl<T: Clone, V: Clone> Clone for ArenaMap<T, V>

fn clone(&self) -> ArenaMap<T, V>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T: Debug, V: Debug> Debug for ArenaMap<T, V>

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

Formats the value using the given formatter.

impl<T, V> Default for ArenaMap<T, V>

fn default() -> Self

Returns the “default value” for a type.