Struct OccupiedEntry

pub struct OccupiedEntry<'a, K, V> { /* private fields */ }

A view into an occupied entry in an IndexMap. It is part of the Entry enum.

Implementations

impl<'a, K, V> OccupiedEntry<'a, K, V>

pub fn index(&self) -> usize

Return the index of the key-value pair

pub fn key(&self) -> &K

Gets a reference to the entry’s key in the map.

Note that this is not the key that was used to find the entry. There may be an observable difference if the key type has any distinguishing features outside of Hash and Eq, like extra fields or the memory address of an allocation.

pub fn get(&self) -> &V

Gets a reference to the entry’s value in the map.

pub fn get_mut(&mut self) -> &mut V

Gets a mutable reference to the entry’s value in the map.

If you need a reference which may outlive the destruction of the Entry value, see into_mut.

pub fn into_mut(self) -> &'a mut V

Converts into a mutable reference to the entry’s value in the map, with a lifetime bound to the map itself.

pub fn insert(&mut self, value: V) -> V

Sets the value of the entry to value, and returns the entry’s old value.

pub fn remove(self) -> V

👎Deprecated: remove disrupts the map order – use swap_remove or shift_remove for explicit behavior.

Remove the key, value pair stored in the map for this entry, and return the value.

NOTE: This is equivalent to .swap_remove(), replacing this entry’s position with the last element, and it is deprecated in favor of calling that explicitly. If you need to preserve the relative order of the keys in the map, use .shift_remove() instead.

pub fn swap_remove(self) -> V

Remove the key, value pair stored in the map for this entry, and return the 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!

Computes in O(1) time (average).

pub fn shift_remove(self) -> V

Remove the key, value pair stored in the map for this entry, and return the value.

Like Vec::remove, the pair is removed by shifting all of the elements that follow it, preserving their relative order. This perturbs the index of all of those elements!

Computes in O(n) time (average).

pub fn remove_entry(self) -> (K, V)

👎Deprecated: remove_entry disrupts the map order – use swap_remove_entry or shift_remove_entry for explicit behavior.

Remove and return the key, value pair stored in the map for this entry

NOTE: This is equivalent to .swap_remove_entry(), replacing this entry’s position with the last element, and it is deprecated in favor of calling that explicitly. If you need to preserve the relative order of the keys in the map, use .shift_remove_entry() instead.

pub fn swap_remove_entry(self) -> (K, V)

Remove and return the key, value pair stored in the map for this entry

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!

Computes in O(1) time (average).

pub fn shift_remove_entry(self) -> (K, V)

Remove and return the key, value pair stored in the map for this entry

Like Vec::remove, the pair is removed by shifting all of the elements that follow it, preserving their relative order. This perturbs the index of all of those elements!

Computes in O(n) time (average).

pub fn move_index(self, to: usize)

Moves the position of the entry to a new index by shifting all other entries in-between.

This is equivalent to IndexMap::move_index coming from the current .index().

• If self.index() < to, the other pairs will shift down while the targeted pair moves up.
• If self.index() > to, the other pairs will shift up while the targeted pair moves down.

Panics if to is out of bounds.

Computes in O(n) time (average).

pub fn swap_indices(self, other: usize)

Swaps the position of entry with another.

This is equivalent to IndexMap::swap_indices with the current .index() as one of the two being swapped.

Panics if the other index is out of bounds.

Computes in O(1) time (average).

Trait Implementations

impl<K: Debug, V: Debug> Debug for OccupiedEntry<'_, K, V>

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

Formats the value using the given formatter.

impl<'a, K, V> From<IndexedEntry<'a, K, V>> for OccupiedEntry<'a, K, V>

fn from(other: IndexedEntry<'a, K, V>) -> Self

Converts to this type from the input type.

impl<'a, K, V> From<OccupiedEntry<'a, K, V>> for IndexedEntry<'a, K, V>

fn from(other: OccupiedEntry<'a, K, V>) -> Self

Converts to this type from the input type.

impl<K, V> MutableEntryKey for OccupiedEntry<'_, K, V>

Opt-in mutable access to OccupiedEntry keys.

See MutableEntryKey for more information.

type Key = K

fn key_mut(&mut self) -> &mut Self::Key

Gets a mutable reference to the entry’s key, either within the map if occupied, or else the new key that was used to find the entry.