Enum Entry 

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

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

This enum is constructed using SecondaryMap::entry.

Variants

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

An occupied entry.

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

A vacant entry.

Implementations

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

where K: Key,

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

let mut sm = SlotMap::new();
let mut sec = SecondaryMap::new();

let k = sm.insert("poneyland");
let v = sec.entry(k).unwrap().or_insert(10);
assert_eq!(*v, 10);
*sec.entry(k).unwrap().or_insert(1) *= 2;
assert_eq!(sec[k], 20);

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

where F: FnOnce() -> 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

let mut sm = SlotMap::new();
let mut sec = SecondaryMap::new();

let k = sm.insert(1);
let v = sec.entry(k).unwrap().or_insert_with(|| "foobar".to_string());
assert_eq!(v, &"foobar");

pub fn key(&self) -> K

Returns this entry’s key.

Examples

let mut sm = SlotMap::new();
let mut sec: SecondaryMap<_, ()> = SecondaryMap::new();

let k = sm.insert(1);
let entry = sec.entry(k).unwrap();
assert_eq!(entry.key(), k);

pub fn and_modify<F>(self, f: F) -> Entry<'a, K, V>

where F: FnOnce(&mut V),

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

Examples

let mut sm = SlotMap::new();
let mut sec = SecondaryMap::new();

let k = sm.insert(1);
sec.insert(k, 0);
sec.entry(k).unwrap().and_modify(|x| *x = 1);

assert_eq!(sec[k], 1)

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

where K: Key, V: Default,

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

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

let mut sm = SlotMap::new();
let mut sec: SecondaryMap<_, Option<i32>> = SecondaryMap::new();

let k = sm.insert(1);
sec.entry(k).unwrap().or_default();
assert_eq!(sec[k], None)

Trait Implementations

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

where K: Debug + Key, V: Debug,

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

Formats the value using the given formatter.

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 24 bytes

Size for each variant:

• Occupied: 16 bytes
• Vacant: 16 bytes