pub enum Entry<'a, K: 'a, V: 'a> { Occupied(OccupiedEntry<'a, K, V>), Vacant(VacantEntry<'a, K, V>), }
A view into a single entry in a map, which may either be vacant or occupied.
This enum
is constructed from the entry
method on HashMap
.
Occupied(OccupiedEntry<'a, K, V>)
An occupied entry.
Vacant(VacantEntry<'a, K, V>)
A vacant entry.
impl<'a, K, V> Entry<'a, K, V>
[src]pub fn or_insert(self, default: V) -> &'a mut V
[src]impl<'a, I> Iterator for &'a mut I where I: Iterator + ?Sized, type Item = <I as Iterator>::Item; impl<'a, R: Read + ?Sized> Read for &'a mut R impl<'a, W: Write + ?Sized> Write for &'a 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.
use std::collections::HashMap; let mut map: HashMap<&str, u32> = HashMap::new(); map.entry("poneyland").or_insert(12); assert_eq!(map["poneyland"], 12); *map.entry("poneyland").or_insert(12) += 10; assert_eq!(map["poneyland"], 22);
pub fn or_insert_with<F: FnOnce() -> V>(self, default: F) -> &'a mut V
[src]impl<'a, I> Iterator for &'a mut I where I: Iterator + ?Sized, type Item = <I as Iterator>::Item; impl<'a, R: Read + ?Sized> Read for &'a mut R impl<'a, W: Write + ?Sized> Write for &'a 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.
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());
pub fn key(&self) -> &K
[src]impl<'a, I> Iterator for &'a mut I where I: Iterator + ?Sized, type Item = <I as Iterator>::Item; impl<'a, R: Read + ?Sized> Read for &'a mut R impl<'a, W: Write + ?Sized> Write for &'a mut W
Returns a reference to this entry's key.
use std::collections::HashMap; let mut map: HashMap<&str, u32> = HashMap::new(); assert_eq!(map.entry("poneyland").key(), &"poneyland");
pub fn and_modify<F>(self, f: F) -> Self where
F: FnOnce(&mut V),
[src]Provides in-place mutable access to an occupied entry before any potential inserts into the map.
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);
impl<'a, K, V: Default> Entry<'a, K, V>
[src]pub fn or_default(self) -> &'a mut V
[src]impl<'a, I> Iterator for &'a mut I where I: Iterator + ?Sized, type Item = <I as Iterator>::Item; impl<'a, R: Read + ?Sized> Read for &'a mut R impl<'a, W: Write + ?Sized> Write for &'a 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.
use std::collections::HashMap; let mut map: HashMap<&str, Option<u32>> = HashMap::new(); map.entry("poneyland").or_default(); assert_eq!(map["poneyland"], None);
impl<T, U> TryFrom for T where
T: From<U>,
[src]type Error = !
The type returned in the event of a conversion error.
fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>
[src]Performs the conversion.
impl<T> From for T
[src]impl<T, U> TryInto for T where
U: TryFrom<T>,
[src]type Error = <U as TryFrom<T>>::Error
The type returned in the event of a conversion error.
fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>
[src]Performs the conversion.
impl<T, U> Into for T where
U: From<T>,
[src]impl<T> Borrow for T where
T: ?Sized,
[src]fn borrow(&self) -> &T
[src]impl<'a, I> Iterator for &'a mut I where I: Iterator + ?Sized, type Item = <I as Iterator>::Item; impl<'a, R: Read + ?Sized> Read for &'a mut R impl<'a, W: Write + ?Sized> Write for &'a mut W
Immutably borrows from an owned value. Read more
impl<T> BorrowMut for T where
T: ?Sized,
[src]fn borrow_mut(&mut self) -> &mut T
[src]impl<'a, I> Iterator for &'a mut I where I: Iterator + ?Sized, type Item = <I as Iterator>::Item; impl<'a, R: Read + ?Sized> Read for &'a mut R impl<'a, W: Write + ?Sized> Write for &'a mut W
Mutably borrows from an owned value. Read more
impl<T> Any for T where
T: 'static + ?Sized,
[src]fn get_type_id(&self) -> TypeId
[src]Gets the TypeId
of self
. Read more
© 2010 The Rust Project Developers
Licensed under the Apache License, Version 2.0 or the MIT license, at your option.
https://doc.rust-lang.org/std/collections/hash_map/enum.Entry.html