pub struct VacantEntry<'a, K: 'a, V: 'a> { /* fields omitted */ }
A view into a vacant entry in a HashMap
.
It is part of the Entry
enum.
Gets a reference to the key that would be used when inserting a value
through the VacantEntry
.
use std::collections::HashMap;
let mut map: HashMap<&str, u32> = HashMap::new();
assert_eq!(map.entry("poneyland").key(), &"poneyland");
Take ownership of the key.
use std::collections::HashMap;
use std::collections::hash_map::Entry;
let mut map: HashMap<&str, u32> = HashMap::new();
if let Entry::Vacant(v) = map.entry("poneyland") {
v.into_key();
}
Sets the value of the entry with the VacantEntry's key,
and returns a mutable reference to it.
use std::collections::HashMap;
use std::collections::hash_map::Entry;
let mut map: HashMap<&str, u32> = HashMap::new();
if let Entry::Vacant(o) = map.entry("poneyland") {
o.insert(37);
}
assert_eq!(map["poneyland"], 37);
Formats the value using the given formatter. Read more