pub struct RawOccupiedEntryMut<'a, K, V, S, A = Global>
where A: Allocator,
{ /* private fields */ }
Expand description

A view into an occupied entry in a HashMap. It is part of the RawEntryMut enum.

Examples

use core::hash::{BuildHasher, Hash};
use hashbrown::hash_map::{HashMap, RawEntryMut, RawOccupiedEntryMut};

let mut map = HashMap::new();
map.extend([("a", 10), ("b", 20), ("c", 30)]);

fn compute_hash<K: Hash + ?Sized, S: BuildHasher>(hash_builder: &S, key: &K) -> u64 {
    use core::hash::Hasher;
    let mut state = hash_builder.build_hasher();
    key.hash(&mut state);
    state.finish()
}

let _raw_o: RawOccupiedEntryMut<_, _, _> = map.raw_entry_mut().from_key(&"a").insert("a", 100);
assert_eq!(map.len(), 3);

// Existing key (insert and update)
match map.raw_entry_mut().from_key(&"a") {
    RawEntryMut::Vacant(_) => unreachable!(),
    RawEntryMut::Occupied(mut view) => {
        assert_eq!(view.get(), &100);
        let v = view.get_mut();
        let new_v = (*v) * 10;
        *v = new_v;
        assert_eq!(view.insert(1111), 1000);
    }
}

assert_eq!(map[&"a"], 1111);
assert_eq!(map.len(), 3);

// Existing key (take)
let hash = compute_hash(map.hasher(), &"c");
match map.raw_entry_mut().from_key_hashed_nocheck(hash, &"c") {
    RawEntryMut::Vacant(_) => unreachable!(),
    RawEntryMut::Occupied(view) => {
        assert_eq!(view.remove_entry(), ("c", 30));
    }
}
assert_eq!(map.raw_entry().from_key(&"c"), None);
assert_eq!(map.len(), 2);

let hash = compute_hash(map.hasher(), &"b");
match map.raw_entry_mut().from_hash(hash, |q| *q == "b") {
    RawEntryMut::Vacant(_) => unreachable!(),
    RawEntryMut::Occupied(view) => {
        assert_eq!(view.remove_entry(), ("b", 20));
    }
}
assert_eq!(map.get(&"b"), None);
assert_eq!(map.len(), 1);

Implementations§

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impl<'a, K, V, S, A> RawOccupiedEntryMut<'a, K, V, S, A>
where A: Allocator,

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pub fn key(&self) -> &K

Gets a reference to the key in the entry.

Examples
use hashbrown::hash_map::{HashMap, RawEntryMut};

let mut map: HashMap<&str, u32> = [("a", 100), ("b", 200)].into();

match map.raw_entry_mut().from_key(&"a") {
    RawEntryMut::Vacant(_) => panic!(),
    RawEntryMut::Occupied(o) => assert_eq!(o.key(), &"a")
}
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pub fn key_mut(&mut self) -> &mut K

Gets a mutable reference to the key in the entry.

Examples
use hashbrown::hash_map::{HashMap, RawEntryMut};
use std::rc::Rc;

let key_one = Rc::new("a");
let key_two = Rc::new("a");

let mut map: HashMap<Rc<&str>, u32> = HashMap::new();
map.insert(key_one.clone(), 10);

assert_eq!(map[&key_one], 10);
assert!(Rc::strong_count(&key_one) == 2 && Rc::strong_count(&key_two) == 1);

match map.raw_entry_mut().from_key(&key_one) {
    RawEntryMut::Vacant(_) => panic!(),
    RawEntryMut::Occupied(mut o) => {
        *o.key_mut() = key_two.clone();
    }
}
assert_eq!(map[&key_two], 10);
assert!(Rc::strong_count(&key_one) == 1 && Rc::strong_count(&key_two) == 2);
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pub fn into_key(self) -> &'a mut K

Converts the entry into a mutable reference to the key in the entry with a lifetime bound to the map itself.

Examples
use hashbrown::hash_map::{HashMap, RawEntryMut};
use std::rc::Rc;

let key_one = Rc::new("a");
let key_two = Rc::new("a");

let mut map: HashMap<Rc<&str>, u32> = HashMap::new();
map.insert(key_one.clone(), 10);

assert_eq!(map[&key_one], 10);
assert!(Rc::strong_count(&key_one) == 2 && Rc::strong_count(&key_two) == 1);

let inside_key: &mut Rc<&str>;

match map.raw_entry_mut().from_key(&key_one) {
    RawEntryMut::Vacant(_) => panic!(),
    RawEntryMut::Occupied(o) => inside_key = o.into_key(),
}
*inside_key = key_two.clone();

assert_eq!(map[&key_two], 10);
assert!(Rc::strong_count(&key_one) == 1 && Rc::strong_count(&key_two) == 2);
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pub fn get(&self) -> &V

Gets a reference to the value in the entry.

Examples
use hashbrown::hash_map::{HashMap, RawEntryMut};

let mut map: HashMap<&str, u32> = [("a", 100), ("b", 200)].into();

match map.raw_entry_mut().from_key(&"a") {
    RawEntryMut::Vacant(_) => panic!(),
    RawEntryMut::Occupied(o) => assert_eq!(o.get(), &100),
}
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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.

Examples
use hashbrown::hash_map::{HashMap, RawEntryMut};

let mut map: HashMap<&str, u32> = [("a", 100), ("b", 200)].into();

let value: &mut u32;

match map.raw_entry_mut().from_key(&"a") {
    RawEntryMut::Vacant(_) => panic!(),
    RawEntryMut::Occupied(o) => value = o.into_mut(),
}
*value += 900;

assert_eq!(map[&"a"], 1000);
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pub fn get_mut(&mut self) -> &mut V

Gets a mutable reference to the value in the entry.

Examples
use hashbrown::hash_map::{HashMap, RawEntryMut};

let mut map: HashMap<&str, u32> = [("a", 100), ("b", 200)].into();

match map.raw_entry_mut().from_key(&"a") {
    RawEntryMut::Vacant(_) => panic!(),
    RawEntryMut::Occupied(mut o) => *o.get_mut() += 900,
}

assert_eq!(map[&"a"], 1000);
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pub fn get_key_value(&self) -> (&K, &V)

Gets a reference to the key and value in the entry.

Examples
use hashbrown::hash_map::{HashMap, RawEntryMut};

let mut map: HashMap<&str, u32> = [("a", 100), ("b", 200)].into();

match map.raw_entry_mut().from_key(&"a") {
    RawEntryMut::Vacant(_) => panic!(),
    RawEntryMut::Occupied(o) => assert_eq!(o.get_key_value(), (&"a", &100)),
}
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pub fn get_key_value_mut(&mut self) -> (&mut K, &mut V)

Gets a mutable reference to the key and value in the entry.

Examples
use hashbrown::hash_map::{HashMap, RawEntryMut};
use std::rc::Rc;

let key_one = Rc::new("a");
let key_two = Rc::new("a");

let mut map: HashMap<Rc<&str>, u32> = HashMap::new();
map.insert(key_one.clone(), 10);

assert_eq!(map[&key_one], 10);
assert!(Rc::strong_count(&key_one) == 2 && Rc::strong_count(&key_two) == 1);

match map.raw_entry_mut().from_key(&key_one) {
    RawEntryMut::Vacant(_) => panic!(),
    RawEntryMut::Occupied(mut o) => {
        let (inside_key, inside_value) = o.get_key_value_mut();
        *inside_key = key_two.clone();
        *inside_value = 100;
    }
}
assert_eq!(map[&key_two], 100);
assert!(Rc::strong_count(&key_one) == 1 && Rc::strong_count(&key_two) == 2);
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pub fn into_key_value(self) -> (&'a mut K, &'a mut V)

Converts the OccupiedEntry into a mutable reference to the key and value in the entry with a lifetime bound to the map itself.

Examples
use hashbrown::hash_map::{HashMap, RawEntryMut};
use std::rc::Rc;

let key_one = Rc::new("a");
let key_two = Rc::new("a");

let mut map: HashMap<Rc<&str>, u32> = HashMap::new();
map.insert(key_one.clone(), 10);

assert_eq!(map[&key_one], 10);
assert!(Rc::strong_count(&key_one) == 2 && Rc::strong_count(&key_two) == 1);

let inside_key: &mut Rc<&str>;
let inside_value: &mut u32;
match map.raw_entry_mut().from_key(&key_one) {
    RawEntryMut::Vacant(_) => panic!(),
    RawEntryMut::Occupied(o) => {
        let tuple = o.into_key_value();
        inside_key = tuple.0;
        inside_value = tuple.1;
    }
}
*inside_key = key_two.clone();
*inside_value = 100;
assert_eq!(map[&key_two], 100);
assert!(Rc::strong_count(&key_one) == 1 && Rc::strong_count(&key_two) == 2);
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pub fn insert(&mut self, value: V) -> V

Sets the value of the entry, and returns the entry’s old value.

Examples
use hashbrown::hash_map::{HashMap, RawEntryMut};

let mut map: HashMap<&str, u32> = [("a", 100), ("b", 200)].into();

match map.raw_entry_mut().from_key(&"a") {
    RawEntryMut::Vacant(_) => panic!(),
    RawEntryMut::Occupied(mut o) => assert_eq!(o.insert(1000), 100),
}

assert_eq!(map[&"a"], 1000);
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pub fn insert_key(&mut self, key: K) -> K

Sets the value of the entry, and returns the entry’s old value.

Examples
use hashbrown::hash_map::{HashMap, RawEntryMut};
use std::rc::Rc;

let key_one = Rc::new("a");
let key_two = Rc::new("a");

let mut map: HashMap<Rc<&str>, u32> = HashMap::new();
map.insert(key_one.clone(), 10);

assert_eq!(map[&key_one], 10);
assert!(Rc::strong_count(&key_one) == 2 && Rc::strong_count(&key_two) == 1);

match map.raw_entry_mut().from_key(&key_one) {
    RawEntryMut::Vacant(_) => panic!(),
    RawEntryMut::Occupied(mut o) => {
        let old_key = o.insert_key(key_two.clone());
        assert!(Rc::ptr_eq(&old_key, &key_one));
    }
}
assert_eq!(map[&key_two], 10);
assert!(Rc::strong_count(&key_one) == 1 && Rc::strong_count(&key_two) == 2);
source

pub fn remove(self) -> V

Takes the value out of the entry, and returns it.

Examples
use hashbrown::hash_map::{HashMap, RawEntryMut};

let mut map: HashMap<&str, u32> = [("a", 100), ("b", 200)].into();

match map.raw_entry_mut().from_key(&"a") {
    RawEntryMut::Vacant(_) => panic!(),
    RawEntryMut::Occupied(o) => assert_eq!(o.remove(), 100),
}
assert_eq!(map.get(&"a"), None);
source

pub fn remove_entry(self) -> (K, V)

Take the ownership of the key and value from the map.

Examples
use hashbrown::hash_map::{HashMap, RawEntryMut};

let mut map: HashMap<&str, u32> = [("a", 100), ("b", 200)].into();

match map.raw_entry_mut().from_key(&"a") {
    RawEntryMut::Vacant(_) => panic!(),
    RawEntryMut::Occupied(o) => assert_eq!(o.remove_entry(), ("a", 100)),
}
assert_eq!(map.get(&"a"), None);
source

pub fn replace_entry_with<F>(self, f: F) -> RawEntryMut<'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::hash_map::{HashMap, RawEntryMut};

let mut map: HashMap<&str, u32> = [("a", 100), ("b", 200)].into();

let raw_entry = match map.raw_entry_mut().from_key(&"a") {
    RawEntryMut::Vacant(_) => panic!(),
    RawEntryMut::Occupied(o) => o.replace_entry_with(|k, v| {
        assert_eq!(k, &"a");
        assert_eq!(v, 100);
        Some(v + 900)
    }),
};
let raw_entry = match raw_entry {
    RawEntryMut::Vacant(_) => panic!(),
    RawEntryMut::Occupied(o) => o.replace_entry_with(|k, v| {
        assert_eq!(k, &"a");
        assert_eq!(v, 1000);
        None
    }),
};
match raw_entry {
    RawEntryMut::Vacant(_) => { },
    RawEntryMut::Occupied(_) => panic!(),
};
assert_eq!(map.get(&"a"), None);

Trait Implementations§

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impl<K, V, S, A> Debug for RawOccupiedEntryMut<'_, K, V, S, A>
where K: Debug, V: Debug, A: Allocator,

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

Formats the value using the given formatter. Read more
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impl<K, V, S, A> Send for RawOccupiedEntryMut<'_, K, V, S, A>
where K: Send, V: Send, S: Send, A: Send + Allocator,

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impl<K, V, S, A> Sync for RawOccupiedEntryMut<'_, K, V, S, A>
where K: Sync, V: Sync, S: Sync, A: Sync + Allocator,

Auto Trait Implementations§

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impl<'a, K, V, S, A> RefUnwindSafe for RawOccupiedEntryMut<'a, K, V, S, A>

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impl<'a, K, V, S, A> Unpin for RawOccupiedEntryMut<'a, K, V, S, A>

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impl<'a, K, V, S, A = Global> !UnwindSafe for RawOccupiedEntryMut<'a, K, V, S, A>

Blanket Implementations§

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impl<T> Any for T
where T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T, U> AsBindGroupShaderType<U> for T
where U: ShaderType, &'a T: for<'a> Into<U>,

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fn as_bind_group_shader_type(&self, _images: &RenderAssets<Image>) -> U

Return the T ShaderType for self. When used in AsBindGroup derives, it is safe to assume that all images in self exist.
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impl<T> Borrow<T> for T
where T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for T
where T: ?Sized,

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fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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impl<T> Downcast<T> for T

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fn downcast(&self) -> &T

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impl<T> Downcast for T
where T: Any,

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fn into_any(self: Box<T>) -> Box<dyn Any>

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.
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fn into_any_rc(self: Rc<T>) -> Rc<dyn Any>

Convert Rc<Trait> (where Trait: Downcast) to Rc<Any>. Rc<Any> can then be further downcast into Rc<ConcreteType> where ConcreteType implements Trait.
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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.
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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.
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impl<T> DowncastSync for T
where T: Any + Send + Sync,

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fn into_any_arc(self: Arc<T>) -> Arc<dyn Any + Send + Sync>

Convert Arc<Trait> (where Trait: Downcast) to Arc<Any>. Arc<Any> can then be further downcast into Arc<ConcreteType> where ConcreteType implements Trait.
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<S> FromSample<S> for S

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fn from_sample_(s: S) -> S

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impl<T> Instrument for T

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fn instrument(self, span: Span) -> Instrumented<Self>

Instruments this type with the provided Span, returning an Instrumented wrapper. Read more
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fn in_current_span(self) -> Instrumented<Self>

Instruments this type with the current Span, returning an Instrumented wrapper. Read more
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impl<T, U> Into<U> for T
where U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T, U> ToSample<U> for T
where U: FromSample<T>,

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fn to_sample_(self) -> U

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impl<T, U> TryFrom<U> for T
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type Error = Infallible

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impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

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type Error = <U as TryFrom<T>>::Error

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