Enum std::collections::hash_map::RawEntryMut
pub enum RawEntryMut<'a, K: 'a, V: 'a, S: 'a> {
Occupied(RawOccupiedEntryMut<'a, K, V, S>),
Vacant(RawVacantEntryMut<'a, K, V, S>),
}
A view into a single entry in a map, which may either be vacant or occupied.
This is a lower-level version of Entry.
This enum is constructed through the raw_entry_mut method on HashMap, then calling one of the methods of that RawEntryBuilderMut.
Variants
Occupied(RawOccupiedEntryMut<'a, K, V, S>)
An occupied entry.
Tuple Fields of Occupied
0: RawOccupiedEntryMut<'a, K, V, S>Vacant(RawVacantEntryMut<'a, K, V, S>)
A vacant entry.
Tuple Fields of Vacant
0: RawVacantEntryMut<'a, K, V, S>Implementations
impl<'a, K, V, S> RawEntryMut<'a, K, V, S>
pub fn or_insert(self, default_key: K, default_val: V) -> (&'a mut K, &'a mut V) where
K: Hash,
S: BuildHasher,
Ensures a value is in the entry by inserting the default if empty, and returns mutable references to the key and value in the entry.
Examples
#![feature(hash_raw_entry)]
use std::collections::HashMap;
let mut map: HashMap<&str, u32> = HashMap::new();
map.raw_entry_mut().from_key("poneyland").or_insert("poneyland", 3);
assert_eq!(map["poneyland"], 3);
*map.raw_entry_mut().from_key("poneyland").or_insert("poneyland", 10).1 *= 2;
assert_eq!(map["poneyland"], 6);pub fn or_insert_with<F>(self, default: F) -> (&'a mut K, &'a mut V) where
F: FnOnce() -> (K, V),
K: Hash,
S: BuildHasher,
Ensures a value is in the entry by inserting the result of the default function if empty, and returns mutable references to the key and value in the entry.
Examples
#![feature(hash_raw_entry)]
use std::collections::HashMap;
let mut map: HashMap<&str, String> = HashMap::new();
map.raw_entry_mut().from_key("poneyland").or_insert_with(|| {
("poneyland", "hoho".to_string())
});
assert_eq!(map["poneyland"], "hoho".to_string());Provides in-place mutable access to an occupied entry before any potential inserts into the map.
Examples
#![feature(hash_raw_entry)]
use std::collections::HashMap;
let mut map: HashMap<&str, u32> = HashMap::new();
map.raw_entry_mut()
.from_key("poneyland")
.and_modify(|_k, v| { *v += 1 })
.or_insert("poneyland", 42);
assert_eq!(map["poneyland"], 42);
map.raw_entry_mut()
.from_key("poneyland")
.and_modify(|_k, v| { *v += 1 })
.or_insert("poneyland", 0);
assert_eq!(map["poneyland"], 43);Trait Implementations
impl<K: Debug, V: Debug, S> Debug for RawEntryMut<'_, K, V, S>
Auto Trait Implementations
impl<'a, K, V, S> RefUnwindSafe for RawEntryMut<'a, K, V, S> where
K: RefUnwindSafe,
S: RefUnwindSafe,
V: RefUnwindSafe,
impl<'a, K, V, S> Unpin for RawEntryMut<'a, K, V, S>
impl<'a, K, V, S> !UnwindSafe for RawEntryMut<'a, K, V, S>
Blanket Implementations
impl<T> From<T> for T
pub fn from(t: T) -> T
Performs the conversion.
pub fn into(self) -> U
Performs the conversion.
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>
Performs the conversion.
type Error = <U as TryFrom<T>>::Error
The type returned in the event of a conversion error.
pub fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>
Performs the conversion.
© 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.RawEntryMut.html