Enum indexmap::map::Entry

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

Entry for an existing key-value pair or a vacant location to insert one.

Variants§

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

Existing slot with equivalent key.

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

Vacant slot (no equivalent key in the map).

Implementations§

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

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

Inserts the given default value in the entry if it is vacant and returns a mutable reference to it. Otherwise a mutable reference to an already existent value is returned.

Computes in O(1) time (amortized average).

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

Inserts the result of the call function in the entry if it is vacant and returns a mutable reference to it. Otherwise a mutable reference to an already existent value is returned.

Computes in O(1) time (amortized average).

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

Inserts the result of the call function with a reference to the entry’s key if it is vacant, and returns a mutable reference to the new value. Otherwise a mutable reference to an already existent value is returned.

Computes in O(1) time (amortized average).

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pub fn key(&self) -> &K

Gets a reference to the entry’s key, either within the map if occupied, or else the new key that was used to find the entry.

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pub fn index(&self) -> usize

Return the index where the key-value pair exists or will be inserted.

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

Modifies the entry if it is occupied.

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

Inserts a default-constructed value in the entry if it is vacant and returns a mutable reference to it. Otherwise a mutable reference to an already existent value is returned.

Computes in O(1) time (amortized average).

Trait Implementations§

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

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

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

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

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

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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.