Enum Entry

pub enum Entry<'a, V> {
    Occupied(OccupiedEntry<'a, V>),
    Vacant(VacantEntry<'a, V>),
}

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

This enum is constructed from ExtractMap::entry.

Variants

Occupied(OccupiedEntry<'a, V>)

An occupied entry.

Vacant(VacantEntry<'a, V>)

A vacant entry.

Implementations

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

pub fn insert(self, value: V) -> OccupiedEntry<'a, V>

Sets the value of the entry, replacing any existing value if there is one, and returns an OccupiedEntry.

Example

use extract_map::ExtractMap;

let mut map: ExtractMap<u64, User> = ExtractMap::new();
map.insert(User { id: 1, name: "Cat" });

let entry = map.entry(&1).insert(User { id: 1, name: "Fox" });
assert_eq!(entry.get(), &User { id: 1, name: "Fox" });

pub fn or_insert(self, default: V) -> OccupiedEntry<'a, V>

Ensures a value is in the entry by inserting if it was vacant.

Returns an OccupiedEntry pointing to the now-occupied entry.

Example

use extract_map::ExtractMap;

let mut map: ExtractMap<u64, User> = ExtractMap::new();

// Inserts new entry, as the map is empty.
let entry = map.entry(&1).or_insert(User { id: 1, name: "Fox" });
assert_eq!(entry.get(), &User { id: 1, name: "Fox" });

// Does not insert new entry, as there is already a user with ID 1.
let entry = map.entry(&1).or_insert(User { id: 1, name: "Cat" });
assert_eq!(entry.get(), &User { id: 1, name: "Fox" });

pub fn or_insert_with(self, default: impl FnOnce() -> V) -> OccupiedEntry<'a, V>

Ensures a value is in the entry by inserting the result of the function if it was vacant.

Returns an OccupiedEntry pointing to the now-occupied entry.

Example

use extract_map::ExtractMap;

let mut map: ExtractMap<u64, User> = ExtractMap::new();

// Inserts new entry, as the map is empty.
let entry = map.entry(&1).or_insert_with(|| User { id: 1, name: "Fox" });
assert_eq!(entry.get(), &User { id: 1, name: "Fox" });

// Does not insert new entry, as there is already a user with ID 1.
let entry = map.entry(&1).or_insert_with(|| User { id: 1, name: "Cat" });
assert_eq!(entry.get(), &User { id: 1, name: "Fox" });

pub fn and_modify(self, f: impl FnOnce(&mut V)) -> Self

Provides in-place mutable access to an occupied entry, does nothing for a vacant entry.

Example

use extract_map::ExtractMap;

let mut map: ExtractMap<u64, User> = ExtractMap::new();

map.insert(User { id: 1, name: "Cat"});
map.entry(&1).and_modify(|user| user.name = "Fox");

assert_eq!(map.get(&1), Some(&User { id: 1, name: "Fox"}));

Trait Implementations

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

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

Formats the value using the given formatter.