Enum parry3d::utils::hashmap::Entry 1.0.0[−][src]
pub enum Entry<'a, K, V> where
K: 'a,
V: 'a, {
Occupied(OccupiedEntry<'a, K, V>),
Vacant(VacantEntry<'a, K, V>),
}
Expand description
Variants
Occupied(OccupiedEntry<'a, K, V>)
An occupied entry.
Tuple Fields of Occupied
0: OccupiedEntry<'a, K, V>
Vacant(VacantEntry<'a, K, V>)
A vacant entry.
Tuple Fields of Vacant
0: VacantEntry<'a, K, V>
Implementations
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 std::collections::HashMap;
let mut map: HashMap<&str, u32> = HashMap::new();
map.entry("poneyland").or_insert(3);
assert_eq!(map["poneyland"], 3);
*map.entry("poneyland").or_insert(10) *= 2;
assert_eq!(map["poneyland"], 6);
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 std::collections::HashMap;
let mut map: HashMap<&str, String> = HashMap::new();
let s = "hoho".to_string();
map.entry("poneyland").or_insert_with(|| s);
assert_eq!(map["poneyland"], "hoho".to_string());
Ensures a value is in the entry by inserting, if empty, the result of the default function.
This method allows for generating key-derived values for insertion by providing the default
function a reference to the key that was moved during the .entry(key)
method call.
The reference to the moved key is provided so that cloning or copying the key is
unnecessary, unlike with .or_insert_with(|| ... )
.
Examples
use std::collections::HashMap;
let mut map: HashMap<&str, usize> = HashMap::new();
map.entry("poneyland").or_insert_with_key(|key| key.chars().count());
assert_eq!(map["poneyland"], 9);
Returns a reference to this entry’s key.
Examples
use std::collections::HashMap;
let mut map: HashMap<&str, u32> = HashMap::new();
assert_eq!(map.entry("poneyland").key(), &"poneyland");
Provides in-place mutable access to an occupied entry before any potential inserts into the map.
Examples
use std::collections::HashMap;
let mut map: HashMap<&str, u32> = HashMap::new();
map.entry("poneyland")
.and_modify(|e| { *e += 1 })
.or_insert(42);
assert_eq!(map["poneyland"], 42);
map.entry("poneyland")
.and_modify(|e| { *e += 1 })
.or_insert(42);
assert_eq!(map["poneyland"], 43);
🔬 This is a nightly-only experimental API. (entry_insert
)
entry_insert
)Sets the value of the entry, and returns an OccupiedEntry
.
Examples
#![feature(entry_insert)]
use std::collections::HashMap;
let mut map: HashMap<&str, String> = HashMap::new();
let entry = map.entry("poneyland").insert("hoho".to_string());
assert_eq!(entry.key(), &"poneyland");
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 std::collections::HashMap;
let mut map: HashMap<&str, Option<u32>> = HashMap::new();
map.entry("poneyland").or_default();
assert_eq!(map["poneyland"], None);
Trait Implementations
Auto Trait Implementations
impl<'a, K, V> RefUnwindSafe for Entry<'a, K, V> where
K: RefUnwindSafe,
V: RefUnwindSafe,
impl<'a, K, V> !UnwindSafe for Entry<'a, K, V>
Blanket Implementations
Mutably borrows from an owned value. Read more
Convert Box<dyn Trait>
(where Trait: Downcast
) to Box<dyn Any>
. Box<dyn Any>
can
then be further downcast
into Box<ConcreteType>
where ConcreteType
implements Trait
. Read more
Convert Rc<Trait>
(where Trait: Downcast
) to Rc<Any>
. Rc<Any>
can then be
further downcast
into Rc<ConcreteType>
where ConcreteType
implements Trait
. Read more
Convert &Trait
(where Trait: Downcast
) to &Any
. This is needed since Rust cannot
generate &Any
’s vtable from &Trait
’s. Read more
Convert &mut Trait
(where Trait: Downcast
) to &Any
. This is needed since Rust cannot
generate &mut Any
’s vtable from &mut Trait
’s. Read more
The inverse inclusion map: attempts to construct self
from the equivalent element of its
superset. Read more
Checks if self
is actually part of its subset T
(and can be converted to it).
Use with care! Same as self.to_subset
but without any property checks. Always succeeds.
The inclusion map: converts self
to the equivalent element of its superset.