Enum slotmap::secondary::Entry

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

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

This enum is constructed using SecondaryMap::entry.

Variants§

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

An occupied entry.

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

A vacant entry.

Implementations§

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

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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);
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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
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");
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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);
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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
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)
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impl<'a, K: Key, V: Default> Entry<'a, K, V>

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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§

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

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

Formats the value using the given formatter. Read more

Auto Trait Implementations§

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impl<'a, K, V> RefUnwindSafe for Entry<'a, K, V>
where V: RefUnwindSafe,

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impl<'a, K, V> Send for Entry<'a, K, V>
where V: Send,

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impl<'a, K, V> Sync for Entry<'a, K, V>
where V: Sync,

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

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impl<'a, K, V> !UnwindSafe for Entry<'a, K, V>

Blanket Implementations§

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impl<T> Any for T
where T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for T
where T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for T
where T: ?Sized,

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fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T, U> Into<U> for T
where U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T, U> TryFrom<U> for T
where U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
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fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

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type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.