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);
sourcepub fn or_insert_with<F>(self, default: F) -> (&'a mut K, &'a mut V)
🔬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)
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
sourcepub fn and_modify<F>(self, f: F) -> Self
🔬This is a nightly-only experimental API. (hash_raw_entry
#56167)
pub fn and_modify<F>(self, f: F) -> Self
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);
Trait Implementations§
Auto Trait Implementations§
impl<'a, K, V, S> Freeze for RawEntryMut<'a, K, V, S>
impl<'a, K, V, S> RefUnwindSafe for RawEntryMut<'a, K, V, S>
impl<'a, K, V, S> Send for RawEntryMut<'a, K, V, S>
impl<'a, K, V, S> Sync for RawEntryMut<'a, K, V, S>
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§
source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more