Enum std::collections::hash_map::Entry 1.0.0[−][src]
A view into a single entry in a map, which may either be vacant or occupied.
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>
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pub fn or_insert(self, default: V) -> &'a mut VⓘNotable traits for &'_ mut F
impl<'_, F> Future for &'_ mut F where
F: Unpin + Future + ?Sized, type Output = <F as Future>::Output;impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized, type Item = <I as Iterator>::Item;impl<R: Read + ?Sized> Read for &mut Rimpl<W: Write + ?Sized> Write for &mut W
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Notable traits for &'_ mut F
impl<'_, F> Future for &'_ mut F where
F: Unpin + Future + ?Sized, type Output = <F as Future>::Output;impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized, type Item = <I as Iterator>::Item;impl<R: Read + ?Sized> Read for &mut Rimpl<W: Write + ?Sized> Write for &mut W
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
use std::collections::HashMap; let mut map: HashMap<&str, u32> = HashMap::new(); map.entry("poneyland").or_insert(3); assert_eq!(map["poneyland"], 3); *map.entry("poneyland").or_insert(10) *= 2; assert_eq!(map["poneyland"], 6);Run
pub fn or_insert_with<F: FnOnce() -> V>(self, default: F) -> &'a mut VⓘNotable traits for &'_ mut F
impl<'_, F> Future for &'_ mut F where
F: Unpin + Future + ?Sized, type Output = <F as Future>::Output;impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized, type Item = <I as Iterator>::Item;impl<R: Read + ?Sized> Read for &mut Rimpl<W: Write + ?Sized> Write for &mut W
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Notable traits for &'_ mut F
impl<'_, F> Future for &'_ mut F where
F: Unpin + Future + ?Sized, type Output = <F as Future>::Output;impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized, type Item = <I as Iterator>::Item;impl<R: Read + ?Sized> Read for &mut Rimpl<W: Write + ?Sized> Write for &mut W
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
use std::collections::HashMap; let mut map: HashMap<&str, String> = HashMap::new(); let s = "hoho".to_string(); map.entry("poneyland").or_insert_with(|| s); assert_eq!(map["poneyland"], "hoho".to_string());Run
pub fn or_insert_with_key<F: FnOnce(&K) -> V>(self, default: F) -> &'a mut VⓘNotable traits for &'_ mut F
impl<'_, F> Future for &'_ mut F where
F: Unpin + Future + ?Sized, type Output = <F as Future>::Output;impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized, type Item = <I as Iterator>::Item;impl<R: Read + ?Sized> Read for &mut Rimpl<W: Write + ?Sized> Write for &mut W
1.50.0[src]
Notable traits for &'_ mut F
impl<'_, F> Future for &'_ mut F where
F: Unpin + Future + ?Sized, type Output = <F as Future>::Output;impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized, type Item = <I as Iterator>::Item;impl<R: Read + ?Sized> Read for &mut Rimpl<W: Write + ?Sized> Write for &mut W
Ensures a value is in the entry by inserting, if empty, the result of the default function.
This method allows for generating key-derived values for insertion by providing the default
function a reference to the key that was moved during the .entry(key)
method call.
The reference to the moved key is provided so that cloning or copying the key is
unnecessary, unlike with .or_insert_with(|| ... )
.
Examples
use std::collections::HashMap; let mut map: HashMap<&str, usize> = HashMap::new(); map.entry("poneyland").or_insert_with_key(|key| key.chars().count()); assert_eq!(map["poneyland"], 9);Run
pub fn key(&self) -> &KⓘNotable traits for &'_ mut F
impl<'_, F> Future for &'_ mut F where
F: Unpin + Future + ?Sized, type Output = <F as Future>::Output;impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized, type Item = <I as Iterator>::Item;impl<R: Read + ?Sized> Read for &mut Rimpl<W: Write + ?Sized> Write for &mut W
1.10.0[src]
Notable traits for &'_ mut F
impl<'_, F> Future for &'_ mut F where
F: Unpin + Future + ?Sized, type Output = <F as Future>::Output;impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized, type Item = <I as Iterator>::Item;impl<R: Read + ?Sized> Read for &mut Rimpl<W: Write + ?Sized> Write for &mut W
Returns a reference to this entry's key.
Examples
use std::collections::HashMap; let mut map: HashMap<&str, u32> = HashMap::new(); assert_eq!(map.entry("poneyland").key(), &"poneyland");Run
pub fn and_modify<F>(self, f: F) -> Self where
F: FnOnce(&mut V),
1.26.0[src]
F: FnOnce(&mut V),
Provides in-place mutable access to an occupied entry before any potential inserts into the map.
Examples
use std::collections::HashMap; let mut map: HashMap<&str, u32> = HashMap::new(); map.entry("poneyland") .and_modify(|e| { *e += 1 }) .or_insert(42); assert_eq!(map["poneyland"], 42); map.entry("poneyland") .and_modify(|e| { *e += 1 }) .or_insert(42); assert_eq!(map["poneyland"], 43);Run
pub fn insert(self, value: V) -> OccupiedEntry<'a, K, V>
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impl<'a, K, V: Default> Entry<'a, K, V>
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pub fn or_default(self) -> &'a mut VⓘNotable traits for &'_ mut F
impl<'_, F> Future for &'_ mut F where
F: Unpin + Future + ?Sized, type Output = <F as Future>::Output;impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized, type Item = <I as Iterator>::Item;impl<R: Read + ?Sized> Read for &mut Rimpl<W: Write + ?Sized> Write for &mut W
1.28.0[src]
Notable traits for &'_ mut F
impl<'_, F> Future for &'_ mut F where
F: Unpin + Future + ?Sized, type Output = <F as Future>::Output;impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized, type Item = <I as Iterator>::Item;impl<R: Read + ?Sized> Read for &mut Rimpl<W: Write + ?Sized> Write for &mut W
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
use std::collections::HashMap; let mut map: HashMap<&str, Option<u32>> = HashMap::new(); map.entry("poneyland").or_default(); assert_eq!(map["poneyland"], None);Run
Trait Implementations
Auto Trait Implementations
impl<'a, K, V> RefUnwindSafe for Entry<'a, K, V> where
K: RefUnwindSafe,
V: RefUnwindSafe,
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K: RefUnwindSafe,
V: RefUnwindSafe,
impl<'a, K, V> Send for Entry<'a, K, V> where
K: Send,
V: Send,
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K: Send,
V: Send,
impl<'a, K, V> Sync for Entry<'a, K, V> where
K: Sync,
V: Sync,
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K: Sync,
V: Sync,
impl<'a, K, V> Unpin for Entry<'a, K, V> where
K: Unpin,
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K: Unpin,
impl<'a, K, V> !UnwindSafe for Entry<'a, K, V>
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Blanket Implementations
impl<T> Any for T where
T: 'static + ?Sized,
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T: 'static + ?Sized,
impl<T> Borrow<T> for T where
T: ?Sized,
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T: ?Sized,
pub fn borrow(&self) -> &TⓘNotable traits for &'_ mut F
impl<'_, F> Future for &'_ mut F where
F: Unpin + Future + ?Sized, type Output = <F as Future>::Output;impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized, type Item = <I as Iterator>::Item;impl<R: Read + ?Sized> Read for &mut Rimpl<W: Write + ?Sized> Write for &mut W
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Notable traits for &'_ mut F
impl<'_, F> Future for &'_ mut F where
F: Unpin + Future + ?Sized, type Output = <F as Future>::Output;impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized, type Item = <I as Iterator>::Item;impl<R: Read + ?Sized> Read for &mut Rimpl<W: Write + ?Sized> Write for &mut W
impl<T> BorrowMut<T> for T where
T: ?Sized,
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T: ?Sized,
pub fn borrow_mut(&mut self) -> &mut TⓘNotable traits for &'_ mut F
impl<'_, F> Future for &'_ mut F where
F: Unpin + Future + ?Sized, type Output = <F as Future>::Output;impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized, type Item = <I as Iterator>::Item;impl<R: Read + ?Sized> Read for &mut Rimpl<W: Write + ?Sized> Write for &mut W
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Notable traits for &'_ mut F
impl<'_, F> Future for &'_ mut F where
F: Unpin + Future + ?Sized, type Output = <F as Future>::Output;impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized, type Item = <I as Iterator>::Item;impl<R: Read + ?Sized> Read for &mut Rimpl<W: Write + ?Sized> Write for &mut W
impl<T> From<T> for T
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impl<T, U> Into<U> for T where
U: From<T>,
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U: From<T>,
impl<T, U> TryFrom<U> for T where
U: Into<T>,
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U: Into<T>,
type Error = Infallible
The type returned in the event of a conversion error.
pub fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>
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impl<T, U> TryInto<U> for T where
U: TryFrom<T>,
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U: TryFrom<T>,