Enum imbl::hashmap::Entry

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pub enum Entry<'a, K, V, S>
where K: Hash + Eq + Clone, V: Clone, S: BuildHasher,
{ Occupied(OccupiedEntry<'a, K, V, S>), Vacant(VacantEntry<'a, K, V, S>), }
Expand description

A handle for a key and its associated value.

§Performance Note

When using an Entry, the key is only ever hashed once, when you create the Entry. Operations on an Entry will never trigger a rehash, where eg. a contains_key(key) followed by an insert(key, default_value) (the equivalent of Entry::or_insert()) would need to hash the key once for the contains_key and again for the insert. The operations generally perform similarly otherwise.

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

An entry which exists in the map.

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

An entry which doesn’t exist in the map.

Implementations§

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impl<'a, K, V, S> Entry<'a, K, V, S>
where K: 'a + Hash + Eq + Clone, V: 'a + Clone, S: 'a + BuildHasher,

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

Insert the default value provided if there was no value already, and return a mutable reference to the value.

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

Insert the default value from the provided function if there was no value already, and return a mutable reference to the value.

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pub fn or_default(self) -> &'a mut V
where V: Default,

Insert a default value if there was no value already, and return a mutable reference to the value.

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pub fn key(&self) -> &K

Get the key for this entry.

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

Call the provided function to modify the value if the value exists.

Auto Trait Implementations§

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

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impl<'a, K, V, S> RefUnwindSafe for Entry<'a, K, V, S>

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

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

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

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

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.