Enum Entry 

pub enum Entry<'a, K, V, C = Slab<Node<K, V>>> {
    Vacant(VacantEntry<'a, K, V, C>),
    Occupied(OccupiedEntry<'a, K, V, C>),
}

A view into a single entry in a map, which may either be vacant or occupied.

This enum is constructed from the entry method on BTreeMap.

Variants

Vacant(VacantEntry<'a, K, V, C>)

Occupied(OccupiedEntry<'a, K, V, C>)

Implementations

impl<'a, K, V, C> Entry<'a, K, V, C>

where C: SimpleCollectionRef + Slab<Node<K, V>>,

pub fn address(&self) -> Address

Gets the address of the entry in the B-Tree.

pub fn key(&self) -> &K

Returns a reference to this entry’s key.

Examples

use btree_slab::BTreeMap;

let mut map: BTreeMap<&str, usize> = BTreeMap::new();
assert_eq!(map.entry("poneyland").key(), &"poneyland");

impl<'a, K, V, C> Entry<'a, K, V, C>

where C: SimpleCollectionRef + SimpleCollectionMut + SlabMut<Node<K, V>>,

pub fn or_insert(self, default: V) -> &'a mut V

Ensures a value is in the entry by inserting the default if empty, and returns a mutable reference to the value in the entry.

Examples

use btree_slab::BTreeMap;

let mut map: BTreeMap<&str, usize> = BTreeMap::new();
map.entry("poneyland").or_insert(12);

assert_eq!(map["poneyland"], 12);

pub fn or_insert_with<F: FnOnce() -> V>(self, default: F) -> &'a mut V

Ensures a value is in the entry by inserting the result of the default function if empty, and returns a mutable reference to the value in the entry.

Examples

use btree_slab::BTreeMap;

let mut map: BTreeMap<&str, String> = BTreeMap::new();
let s = "hoho".to_string();

map.entry("poneyland").or_insert_with(|| s);

assert_eq!(map["poneyland"], "hoho".to_string());

pub fn or_insert_with_key<F: FnOnce(&K) -> V>(self, default: F) -> &'a mut V

Ensures a value is in the entry by inserting, if empty, the result of the default function, which takes the key as its argument, and returns a mutable reference to the value in the entry.

Examples

use btree_slab::BTreeMap;

let mut map: BTreeMap<&str, usize> = BTreeMap::new();

map.entry("poneyland").or_insert_with_key(|key| key.chars().count());

assert_eq!(map["poneyland"], 9);

pub fn and_modify<F>(self, f: F) -> Self

where F: FnOnce(&mut V),

Provides in-place mutable access to an occupied entry before any potential inserts into the map.

Examples

use btree_slab::BTreeMap;

let mut map: BTreeMap<&str, usize> = BTreeMap::new();

map.entry("poneyland")
   .and_modify(|e| { *e += 1 })
   .or_insert(42);
assert_eq!(map["poneyland"], 42);

map.entry("poneyland")
   .and_modify(|e| { *e += 1 })
   .or_insert(42);
assert_eq!(map["poneyland"], 43);

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

where V: Default,

Ensures a value is in the entry by inserting the default value if empty, and returns a mutable reference to the value in the entry.

Examples

use btree_slab::BTreeMap;

let mut map: BTreeMap<&str, Option<usize>> = BTreeMap::new();
map.entry("poneyland").or_default();

assert_eq!(map["poneyland"], None);

Trait Implementations

impl<'a, K: Debug, V: Debug, C> Debug for Entry<'a, K, V, C>

where C: SimpleCollectionRef + Slab<Node<K, V>>,

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

Formats the value using the given formatter.