Struct hashbrown::hash_map::VacantEntryRef

pub struct VacantEntryRef<'a, 'b, K, Q: ?Sized, V, S, A: Allocator + Clone = Global> { /* private fields */ }

A view into a vacant entry in a HashMap. It is part of the EntryRef enum.

Implementations

impl<'a, 'b, K, Q: ?Sized, V, S, A: Allocator + Clone> VacantEntryRef<'a, 'b, K, Q, V, S, A>

pub fn key(&self) -> &Q where
    K: Borrow<Q>, 

Gets a reference to the key that would be used when inserting a value through the VacantEntryRef.

Examples

use hashbrown::HashMap;

let mut map: HashMap<String, u32> = HashMap::new();
let key: &str = "poneyland";
assert_eq!(map.entry_ref(key).key(), "poneyland");

pub fn into_key(self) -> K where
    K: From<&'b Q>, 

Take ownership of the key.

Examples

use hashbrown::HashMap;
use hashbrown::hash_map::EntryRef;

let mut map: HashMap<String, u32> = HashMap::new();
let key: &str = "poneyland";

if let EntryRef::Vacant(v) = map.entry_ref(key) {
    v.into_key();
}

pub fn insert(self, value: V) -> &'a mut V where
    K: Hash + From<&'b Q>,
    S: BuildHasher, 

Sets the value of the entry with the VacantEntryRef’s key, and returns a mutable reference to it.

Examples

use hashbrown::HashMap;
use hashbrown::hash_map::EntryRef;

let mut map: HashMap<String, u32> = HashMap::new();
let key: &str = "poneyland";

if let EntryRef::Vacant(o) = map.entry_ref(key) {
    o.insert(37);
}
assert_eq!(map["poneyland"], 37);

Trait Implementations

impl<K: Borrow<Q>, Q: ?Sized + Debug, V, S, A: Allocator + Clone> Debug for VacantEntryRef<'_, '_, K, Q, V, S, A>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.