Enum hashbrown::rustc_entry::RustcEntry
source · pub enum RustcEntry<'a, K, V, A = Global>where
A: Allocator + Clone,{
Occupied(RustcOccupiedEntry<'a, K, V, A>),
Vacant(RustcVacantEntry<'a, K, V, A>),
}
Expand description
A view into a single entry in a map, which may either be vacant or occupied.
This enum
is constructed from the rustc_entry
method on HashMap
.
Variants§
Occupied(RustcOccupiedEntry<'a, K, V, A>)
An occupied entry.
Vacant(RustcVacantEntry<'a, K, V, A>)
A vacant entry.
Implementations§
source§impl<'a, K, V, A: Allocator + Clone> RustcEntry<'a, K, V, A>
impl<'a, K, V, A: Allocator + Clone> RustcEntry<'a, K, V, A>
sourcepub fn insert(self, value: V) -> RustcOccupiedEntry<'a, K, V, A>
pub fn insert(self, value: V) -> RustcOccupiedEntry<'a, K, V, A>
Sets the value of the entry, and returns a RustcOccupiedEntry.
Examples
use hashbrown::HashMap;
let mut map: HashMap<&str, u32> = HashMap::new();
let entry = map.rustc_entry("horseyland").insert(37);
assert_eq!(entry.key(), &"horseyland");
sourcepub fn or_insert(self, default: V) -> &'a mut Vwhere
K: Hash,
pub fn or_insert(self, default: V) -> &'a mut Vwhere K: Hash,
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 hashbrown::HashMap;
let mut map: HashMap<&str, u32> = HashMap::new();
map.rustc_entry("poneyland").or_insert(3);
assert_eq!(map["poneyland"], 3);
*map.rustc_entry("poneyland").or_insert(10) *= 2;
assert_eq!(map["poneyland"], 6);
sourcepub fn or_insert_with<F: FnOnce() -> V>(self, default: F) -> &'a mut Vwhere
K: Hash,
pub fn or_insert_with<F: FnOnce() -> V>(self, default: F) -> &'a mut Vwhere K: Hash,
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 hashbrown::HashMap;
let mut map: HashMap<&str, String> = HashMap::new();
let s = "hoho".to_string();
map.rustc_entry("poneyland").or_insert_with(|| s);
assert_eq!(map["poneyland"], "hoho".to_string());
sourcepub fn key(&self) -> &K
pub fn key(&self) -> &K
Returns a reference to this entry’s key.
Examples
use hashbrown::HashMap;
let mut map: HashMap<&str, u32> = HashMap::new();
assert_eq!(map.rustc_entry("poneyland").key(), &"poneyland");
sourcepub fn and_modify<F>(self, f: F) -> Selfwhere
F: FnOnce(&mut V),
pub fn and_modify<F>(self, f: F) -> Selfwhere F: FnOnce(&mut V),
Provides in-place mutable access to an occupied entry before any potential inserts into the map.
Examples
use hashbrown::HashMap;
let mut map: HashMap<&str, u32> = HashMap::new();
map.rustc_entry("poneyland")
.and_modify(|e| { *e += 1 })
.or_insert(42);
assert_eq!(map["poneyland"], 42);
map.rustc_entry("poneyland")
.and_modify(|e| { *e += 1 })
.or_insert(42);
assert_eq!(map["poneyland"], 43);
source§impl<'a, K, V: Default, A: Allocator + Clone> RustcEntry<'a, K, V, A>
impl<'a, K, V: Default, A: Allocator + Clone> RustcEntry<'a, K, V, A>
sourcepub fn or_default(self) -> &'a mut Vwhere
K: Hash,
pub fn or_default(self) -> &'a mut Vwhere K: Hash,
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 hashbrown::HashMap;
let mut map: HashMap<&str, Option<u32>> = HashMap::new();
map.rustc_entry("poneyland").or_default();
assert_eq!(map["poneyland"], None);