pub struct OccupiedEntry<'a, K, V, S, A = Global> where
A: Allocator + Clone, { /* private fields */ }
Expand description
A view into an occupied entry in a HashMap
.
It is part of the Entry
enum.
Implementations
impl<'a, K, V, S, A> OccupiedEntry<'a, K, V, S, A> where
A: Allocator + Clone,
impl<'a, K, V, S, A> OccupiedEntry<'a, K, V, S, A> where
A: Allocator + Clone,
pub fn key(&self) -> &K
pub fn key(&self) -> &K
Gets a reference to the key in the entry.
Examples
use hashbrown::HashMap;
let mut map: HashMap<&str, u32> = HashMap::new();
map.entry("poneyland").or_insert(12);
assert_eq!(map.entry("poneyland").key(), &"poneyland");
pub fn remove_entry(self) -> (K, V)
pub fn remove_entry(self) -> (K, V)
Take the ownership of the key and value from the map.
Examples
use hashbrown::HashMap;
use hashbrown::hash_map::Entry;
let mut map: HashMap<&str, u32> = HashMap::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();
}
assert_eq!(map.contains_key("poneyland"), false);
pub fn get(&self) -> &V
pub fn get(&self) -> &V
Gets a reference to the value in the entry.
Examples
use hashbrown::HashMap;
use hashbrown::hash_map::Entry;
let mut map: HashMap<&str, u32> = HashMap::new();
map.entry("poneyland").or_insert(12);
if let Entry::Occupied(o) = map.entry("poneyland") {
assert_eq!(o.get(), &12);
}
pub fn get_mut(&mut self) -> &mut V
pub fn get_mut(&mut self) -> &mut V
Gets a mutable reference to the value in the entry.
If you need a reference to the OccupiedEntry
which may outlive the
destruction of the Entry
value, see into_mut
.
Examples
use hashbrown::HashMap;
use hashbrown::hash_map::Entry;
let mut map: HashMap<&str, u32> = HashMap::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);
pub fn into_mut(self) -> &'a mut V
pub fn into_mut(self) -> &'a mut V
Converts the OccupiedEntry into a mutable reference to the value in the entry with a lifetime bound to the map itself.
If you need multiple references to the OccupiedEntry
, see get_mut
.
Examples
use hashbrown::HashMap;
use hashbrown::hash_map::Entry;
let mut map: HashMap<&str, u32> = HashMap::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);
pub fn insert(&mut self, value: V) -> V
pub fn insert(&mut self, value: V) -> V
Sets the value of the entry, and returns the entry’s old value.
Examples
use hashbrown::HashMap;
use hashbrown::hash_map::Entry;
let mut map: HashMap<&str, u32> = HashMap::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);
pub fn remove(self) -> V
pub fn remove(self) -> V
Takes the value out of the entry, and returns it.
Examples
use hashbrown::HashMap;
use hashbrown::hash_map::Entry;
let mut map: HashMap<&str, u32> = HashMap::new();
map.entry("poneyland").or_insert(12);
if let Entry::Occupied(o) = map.entry("poneyland") {
assert_eq!(o.remove(), 12);
}
assert_eq!(map.contains_key("poneyland"), false);
pub fn replace_entry(self, value: V) -> (K, V)
pub fn replace_entry(self, value: V) -> (K, V)
Replaces the entry, returning the old key and value. The new key in the hash map will be the key used to create this entry.
Panics
Will panic if this OccupiedEntry was created through Entry::insert
.
Examples
use hashbrown::hash_map::{Entry, HashMap};
use std::rc::Rc;
let mut map: HashMap<Rc<String>, u32> = HashMap::new();
map.insert(Rc::new("Stringthing".to_string()), 15);
let my_key = Rc::new("Stringthing".to_string());
if let Entry::Occupied(entry) = map.entry(my_key) {
// Also replace the key with a handle to our other key.
let (old_key, old_value): (Rc<String>, u32) = entry.replace_entry(16);
}
pub fn replace_key(self) -> K
pub fn replace_key(self) -> K
Replaces the key in the hash map with the key used to create this entry.
Panics
Will panic if this OccupiedEntry was created through Entry::insert
.
Examples
use hashbrown::hash_map::{Entry, HashMap};
use std::rc::Rc;
let mut map: HashMap<Rc<String>, u32> = HashMap::new();
let mut known_strings: Vec<Rc<String>> = Vec::new();
// Initialise known strings, run program, etc.
reclaim_memory(&mut map, &known_strings);
fn reclaim_memory(map: &mut HashMap<Rc<String>, u32>, known_strings: &[Rc<String>] ) {
for s in known_strings {
if let Entry::Occupied(entry) = map.entry(s.clone()) {
// Replaces the entry's key with our version of it in `known_strings`.
entry.replace_key();
}
}
}
pub fn replace_entry_with<F>(self, f: F) -> Entry<'a, K, V, S, A> where
F: FnOnce(&K, V) -> Option<V>,
pub fn replace_entry_with<F>(self, f: F) -> Entry<'a, K, V, S, A> where
F: FnOnce(&K, V) -> Option<V>,
Provides shared access to the key and owned access to the value of the entry and allows to replace or remove it based on the value of the returned option.
Examples
use hashbrown::HashMap;
use hashbrown::hash_map::Entry;
let mut map: HashMap<&str, u32> = HashMap::new();
map.insert("poneyland", 42);
let entry = match map.entry("poneyland") {
Entry::Occupied(e) => {
e.replace_entry_with(|k, v| {
assert_eq!(k, &"poneyland");
assert_eq!(v, 42);
Some(v + 1)
})
}
Entry::Vacant(_) => panic!(),
};
match entry {
Entry::Occupied(e) => {
assert_eq!(e.key(), &"poneyland");
assert_eq!(e.get(), &43);
}
Entry::Vacant(_) => panic!(),
}
assert_eq!(map["poneyland"], 43);
let entry = match map.entry("poneyland") {
Entry::Occupied(e) => e.replace_entry_with(|_k, _v| None),
Entry::Vacant(_) => panic!(),
};
match entry {
Entry::Vacant(e) => {
assert_eq!(e.key(), &"poneyland");
}
Entry::Occupied(_) => panic!(),
}
assert!(!map.contains_key("poneyland"));
Trait Implementations
impl<K, V, S, A> Debug for OccupiedEntry<'_, K, V, S, A> where
K: Debug,
V: Debug,
A: Allocator + Clone,
impl<K, V, S, A> Debug for OccupiedEntry<'_, K, V, S, A> where
K: Debug,
V: Debug,
A: Allocator + Clone,
impl<K, V, S, A> Send for OccupiedEntry<'_, K, V, S, A> where
K: Send,
V: Send,
S: Send,
A: Send + Allocator + Clone,
impl<K, V, S, A> Sync for OccupiedEntry<'_, K, V, S, A> where
K: Sync,
V: Sync,
S: Sync,
A: Sync + Allocator + Clone,
Auto Trait Implementations
impl<'a, K, V, S, A> RefUnwindSafe for OccupiedEntry<'a, K, V, S, A> where
A: RefUnwindSafe,
K: RefUnwindSafe,
S: RefUnwindSafe,
V: RefUnwindSafe,
impl<'a, K, V, S, A> Unpin for OccupiedEntry<'a, K, V, S, A> where
K: Unpin,
impl<'a, K, V, S, A = Global> !UnwindSafe for OccupiedEntry<'a, K, V, S, A>
Blanket Implementations
impl<T, U> AsBindGroupShaderType<U> for T where
U: ShaderType,
&'a T: for<'a> Into<U>,
impl<T, U> AsBindGroupShaderType<U> for T where
U: ShaderType,
&'a T: for<'a> Into<U>,
fn as_bind_group_shader_type(
&self,
_images: &HashMap<Handle<Image>, <Image as RenderAsset>::PreparedAsset, RandomState, Global>
) -> U
fn as_bind_group_shader_type(
&self,
_images: &HashMap<Handle<Image>, <Image as RenderAsset>::PreparedAsset, RandomState, Global>
) -> U
Return the T
ShaderType
for self
. When used in AsBindGroup
derives, it is safe to assume that all images in self
exist. Read more
sourceimpl<T> BorrowMut<T> for T where
T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
const: unstable · sourcefn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
impl<T> Downcast for T where
T: Any,
impl<T> Downcast for T where
T: Any,
fn into_any(self: Box<T, Global>) -> Box<dyn Any + 'static, Global>
fn into_any(self: Box<T, Global>) -> Box<dyn Any + 'static, Global>
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
fn into_any_rc(self: Rc<T>) -> Rc<dyn Any + 'static>
fn into_any_rc(self: Rc<T>) -> Rc<dyn Any + 'static>
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
fn as_any(&self) -> &(dyn Any + 'static)
fn as_any(&self) -> &(dyn Any + 'static)
Convert &Trait
(where Trait: Downcast
) to &Any
. This is needed since Rust cannot
generate &Any
’s vtable from &Trait
’s. Read more
fn as_any_mut(&mut self) -> &mut (dyn Any + 'static)
fn as_any_mut(&mut self) -> &mut (dyn Any + 'static)
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
sourceimpl<T> Instrument for T
impl<T> Instrument for T
sourcefn instrument(self, span: Span) -> Instrumented<Self>ⓘNotable traits for Instrumented<T>impl<T> Future for Instrumented<T> where
T: Future, type Output = <T as Future>::Output;
fn instrument(self, span: Span) -> Instrumented<Self>ⓘNotable traits for Instrumented<T>impl<T> Future for Instrumented<T> where
T: Future, type Output = <T as Future>::Output;
T: Future, type Output = <T as Future>::Output;
sourcefn in_current_span(self) -> Instrumented<Self>ⓘNotable traits for Instrumented<T>impl<T> Future for Instrumented<T> where
T: Future, type Output = <T as Future>::Output;
fn in_current_span(self) -> Instrumented<Self>ⓘNotable traits for Instrumented<T>impl<T> Future for Instrumented<T> where
T: Future, type Output = <T as Future>::Output;
T: Future, type Output = <T as Future>::Output;
sourceimpl<T> WithSubscriber for T
impl<T> WithSubscriber for T
sourcefn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self>ⓘNotable traits for WithDispatch<T>impl<T> Future for WithDispatch<T> where
T: Future, type Output = <T as Future>::Output;
where
S: Into<Dispatch>,
fn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self>ⓘNotable traits for WithDispatch<T>impl<T> Future for WithDispatch<T> where
T: Future, type Output = <T as Future>::Output;
where
S: Into<Dispatch>,
T: Future, type Output = <T as Future>::Output;
Attaches the provided Subscriber
to this type, returning a
WithDispatch
wrapper. Read more
sourcefn with_current_subscriber(self) -> WithDispatch<Self>ⓘNotable traits for WithDispatch<T>impl<T> Future for WithDispatch<T> where
T: Future, type Output = <T as Future>::Output;
fn with_current_subscriber(self) -> WithDispatch<Self>ⓘNotable traits for WithDispatch<T>impl<T> Future for WithDispatch<T> where
T: Future, type Output = <T as Future>::Output;
T: Future, type Output = <T as Future>::Output;
Attaches the current default Subscriber
to this type, returning a
WithDispatch
wrapper. Read more