Entry

Enum 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 in an IndexMap or a vacant location to insert one.

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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).

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

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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 insert_entry(self, value: V) -> OccupiedEntry<'a, K, V>

Sets the value of the entry (after inserting if vacant), and returns an OccupiedEntry.

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

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

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

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

Formats the value using the given formatter. Read more
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impl<K, V> MutableEntryKey for Entry<'_, K, V>

Opt-in mutable access to Entry keys.

See MutableEntryKey for more information.

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type Key = K

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fn key_mut(&mut self) -> &mut <Entry<'_, K, V> as MutableEntryKey>::Key

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

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>

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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> Downcast for T
where T: Any,

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fn into_any(self: Box<T>) -> Box<dyn Any>

Converts Box<dyn Trait> (where Trait: Downcast) to Box<dyn Any>, which can then be downcast into Box<dyn ConcreteType> where ConcreteType implements Trait.
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fn into_any_rc(self: Rc<T>) -> Rc<dyn Any>

Converts Rc<Trait> (where Trait: Downcast) to Rc<Any>, which can then be further downcast into Rc<ConcreteType> where ConcreteType implements Trait.
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fn as_any(&self) -> &(dyn Any + 'static)

Converts &Trait (where Trait: Downcast) to &Any. This is needed since Rust cannot generate &Any’s vtable from &Trait’s.
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fn as_any_mut(&mut self) -> &mut (dyn Any + 'static)

Converts &mut Trait (where Trait: Downcast) to &Any. This is needed since Rust cannot generate &mut Any’s vtable from &mut Trait’s.
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impl<T> DowncastSend for T
where T: Any + Send,

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fn into_any_send(self: Box<T>) -> Box<dyn Any + Send>

Converts Box<Trait> (where Trait: DowncastSend) to Box<dyn Any + Send>, which can then be downcast into Box<ConcreteType> where ConcreteType implements Trait.
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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, W> HasTypeWitness<W> for T
where W: MakeTypeWitness<Arg = T>, T: ?Sized,

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const WITNESS: W = W::MAKE

A constant of the type witness
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impl<T> Identity for T
where T: ?Sized,

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const TYPE_EQ: TypeEq<T, <T as Identity>::Type> = TypeEq::NEW

Proof that Self is the same type as Self::Type, provides methods for casting between Self and Self::Type.
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type Type = T

The same type as Self, used to emulate type equality bounds (T == U) with associated type equality constraints (T: Identity<Type = U>).
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impl<T> Instrument for T

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fn instrument(self, span: Span) -> Instrumented<Self>

Instruments this type with the provided Span, returning an Instrumented wrapper. Read more
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fn in_current_span(self) -> Instrumented<Self>

Instruments this type with the current Span, returning an Instrumented wrapper. Read more
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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> IntoResult<T> for T

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fn into_result(self) -> Result<T, RunSystemError>

Converts this type into the system output type.
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impl<A> Is for A
where A: Any,

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fn is<T>() -> bool
where T: Any,

Checks if the current type “is” another type, using a TypeId equality comparison. This is most useful in the context of generic logic. Read more
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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.
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impl<T> WithSubscriber for T

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fn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self>
where S: Into<Dispatch>,

Attaches the provided Subscriber to this type, returning a WithDispatch wrapper. Read more
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fn with_current_subscriber(self) -> WithDispatch<Self>

Attaches the current default Subscriber to this type, returning a WithDispatch wrapper. Read more
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impl<T> ConditionalSend for T
where T: Send,

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impl<T> WasmNotSend for T
where T: Send,

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impl<T> WasmNotSendSync for T

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impl<T> WasmNotSync for T
where T: Sync,