Enum std::collections::hash_map::RawEntryMut
source · pub enum RawEntryMut<'a, K: 'a, V: 'a, S: 'a> {
Occupied(RawOccupiedEntryMut<'a, K, V, S>),
Vacant(RawVacantEntryMut<'a, K, V, S>),
}
🔬This is a nightly-only experimental API. (
hash_raw_entry
#56167)Expand description
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>)
🔬This is a nightly-only experimental API. (
hash_raw_entry
#56167)An occupied entry.
Vacant(RawVacantEntryMut<'a, K, V, S>)
🔬This is a nightly-only experimental API. (
hash_raw_entry
#56167)A vacant entry.
Implementations§
source§impl<'a, K, V, S> RawEntryMut<'a, K, V, S>
impl<'a, K, V, S> RawEntryMut<'a, K, V, S>
sourcepub fn or_insert(self, default_key: K, default_val: V) -> (&'a mut K, &'a mut V)where
K: Hash,
S: BuildHasher,
🔬This is a nightly-only experimental API. (hash_raw_entry
#56167)
pub fn or_insert(self, default_key: K, default_val: V) -> (&'a mut K, &'a mut V)where K: Hash, S: BuildHasher,
hash_raw_entry
#56167)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);
Runsourcepub fn or_insert_with<F>(self, default: F) -> (&'a mut K, &'a mut V)where
F: FnOnce() -> (K, V),
K: Hash,
S: BuildHasher,
🔬This is a nightly-only experimental API. (hash_raw_entry
#56167)
pub fn or_insert_with<F>(self, default: F) -> (&'a mut K, &'a mut V)where F: FnOnce() -> (K, V), K: Hash, S: BuildHasher,
hash_raw_entry
#56167)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());
Runsourcepub fn and_modify<F>(self, f: F) -> Selfwhere
F: FnOnce(&mut K, &mut V),
🔬This is a nightly-only experimental API. (hash_raw_entry
#56167)
pub fn and_modify<F>(self, f: F) -> Selfwhere F: FnOnce(&mut K, &mut V),
hash_raw_entry
#56167)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);
Run