Struct sp_std::collections::btree_map::OccupiedEntry
1.0.0 · source · [−]pub struct OccupiedEntry<'a, K, V> where
K: 'a,
V: 'a, { /* private fields */ }
Expand description
A view into an occupied entry in a BTreeMap
.
It is part of the Entry
enum.
Implementations
Gets a reference to the key in the entry.
Examples
use std::collections::BTreeMap;
let mut map: BTreeMap<&str, usize> = BTreeMap::new();
map.entry("poneyland").or_insert(12);
assert_eq!(map.entry("poneyland").key(), &"poneyland");
Take ownership of the key and value from the map.
Examples
use std::collections::BTreeMap;
use std::collections::btree_map::Entry;
let mut map: BTreeMap<&str, usize> = BTreeMap::new();
map.entry("poneyland").or_insert(12);
if let Entry::Occupied(o) = map.entry("poneyland") {
// We delete the entry from the map.
o.remove_entry();
}
// If now try to get the value, it will panic:
// println!("{}", map["poneyland"]);
Gets a reference to the value in the entry.
Examples
use std::collections::BTreeMap;
use std::collections::btree_map::Entry;
let mut map: BTreeMap<&str, usize> = BTreeMap::new();
map.entry("poneyland").or_insert(12);
if let Entry::Occupied(o) = map.entry("poneyland") {
assert_eq!(o.get(), &12);
}
Gets a mutable reference to the value in the entry.
If you need a reference to the OccupiedEntry
that may outlive the
destruction of the Entry
value, see into_mut
.
Examples
use std::collections::BTreeMap;
use std::collections::btree_map::Entry;
let mut map: BTreeMap<&str, usize> = BTreeMap::new();
map.entry("poneyland").or_insert(12);
assert_eq!(map["poneyland"], 12);
if let Entry::Occupied(mut o) = map.entry("poneyland") {
*o.get_mut() += 10;
assert_eq!(*o.get(), 22);
// We can use the same Entry multiple times.
*o.get_mut() += 2;
}
assert_eq!(map["poneyland"], 24);
Converts the entry into a mutable reference to its value.
If you need multiple references to the OccupiedEntry
, see get_mut
.
Examples
use std::collections::BTreeMap;
use std::collections::btree_map::Entry;
let mut map: BTreeMap<&str, usize> = BTreeMap::new();
map.entry("poneyland").or_insert(12);
assert_eq!(map["poneyland"], 12);
if let Entry::Occupied(o) = map.entry("poneyland") {
*o.into_mut() += 10;
}
assert_eq!(map["poneyland"], 22);
Sets the value of the entry with the OccupiedEntry
’s key,
and returns the entry’s old value.
Examples
use std::collections::BTreeMap;
use std::collections::btree_map::Entry;
let mut map: BTreeMap<&str, usize> = BTreeMap::new();
map.entry("poneyland").or_insert(12);
if let Entry::Occupied(mut o) = map.entry("poneyland") {
assert_eq!(o.insert(15), 12);
}
assert_eq!(map["poneyland"], 15);
Takes the value of the entry out of the map, and returns it.
Examples
use std::collections::BTreeMap;
use std::collections::btree_map::Entry;
let mut map: BTreeMap<&str, usize> = BTreeMap::new();
map.entry("poneyland").or_insert(12);
if let Entry::Occupied(o) = map.entry("poneyland") {
assert_eq!(o.remove(), 12);
}
// If we try to get "poneyland"'s value, it'll panic:
// println!("{}", map["poneyland"]);