pub enum RawEntryMut<'a, K: 'a, V: 'a, S: 'a> {
    Occupied(RawOccupiedEntryMut<'a, K, V, S>),
    Vacant(RawVacantEntryMut<'a, K, V, S>),
}
🔬This is a nightly-only experimental API. (hash_raw_entry #56167)
Expand description

A view into a single entry in a map, which may either be vacant or occupied.

This is a lower-level version of Entry.

This enum is constructed through the raw_entry_mut method on HashMap, then calling one of the methods of that RawEntryBuilderMut.

Variants§

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Occupied(RawOccupiedEntryMut<'a, K, V, S>)

🔬This is a nightly-only experimental API. (hash_raw_entry #56167)

An occupied entry.

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Vacant(RawVacantEntryMut<'a, K, V, S>)

🔬This is a nightly-only experimental API. (hash_raw_entry #56167)

A vacant entry.

Implementations§

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impl<'a, K, V, S> RawEntryMut<'a, K, V, S>

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pub fn or_insert(self, default_key: K, default_val: V) -> (&'a mut K, &'a mut V)where
    K: Hash,
    S: BuildHasher,

🔬This is a nightly-only experimental API. (hash_raw_entry #56167)

Ensures a value is in the entry by inserting the default if empty, and returns mutable references to the key and value in the entry.

Examples
#![feature(hash_raw_entry)]
use std::collections::HashMap;

let mut map: HashMap<&str, u32> = HashMap::new();

map.raw_entry_mut().from_key("poneyland").or_insert("poneyland", 3);
assert_eq!(map["poneyland"], 3);

*map.raw_entry_mut().from_key("poneyland").or_insert("poneyland", 10).1 *= 2;
assert_eq!(map["poneyland"], 6);
Run
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pub fn or_insert_with<F>(self, default: F) -> (&'a mut K, &'a mut V)where
    F: FnOnce() -> (K, V),
    K: Hash,
    S: BuildHasher,

🔬This is a nightly-only experimental API. (hash_raw_entry #56167)

Ensures a value is in the entry by inserting the result of the default function if empty, and returns mutable references to the key and value in the entry.

Examples
#![feature(hash_raw_entry)]
use std::collections::HashMap;

let mut map: HashMap<&str, String> = HashMap::new();

map.raw_entry_mut().from_key("poneyland").or_insert_with(|| {
    ("poneyland", "hoho".to_string())
});

assert_eq!(map["poneyland"], "hoho".to_string());
Run
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pub fn and_modify<F>(self, f: F) -> Selfwhere
    F: FnOnce(&mut K, &mut V),

🔬This is a nightly-only experimental API. (hash_raw_entry #56167)

Provides in-place mutable access to an occupied entry before any potential inserts into the map.

Examples
#![feature(hash_raw_entry)]
use std::collections::HashMap;

let mut map: HashMap<&str, u32> = HashMap::new();

map.raw_entry_mut()
   .from_key("poneyland")
   .and_modify(|_k, v| { *v += 1 })
   .or_insert("poneyland", 42);
assert_eq!(map["poneyland"], 42);

map.raw_entry_mut()
   .from_key("poneyland")
   .and_modify(|_k, v| { *v += 1 })
   .or_insert("poneyland", 0);
assert_eq!(map["poneyland"], 43);
Run

Trait Implementations§

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impl<K: Debug, V: Debug, S> Debug for RawEntryMut<'_, K, V, S>

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

Formats the value using the given formatter. Read more

Auto Trait Implementations§

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impl<'a, K, V, S> RefUnwindSafe for RawEntryMut<'a, K, V, S>where
    K: RefUnwindSafe,
    S: RefUnwindSafe,
    V: RefUnwindSafe,

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impl<'a, K, V, S> Send for RawEntryMut<'a, K, V, S>where
    K: Send,
    S: Send + Sync,
    V: Send,

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impl<'a, K, V, S> Sync for RawEntryMut<'a, K, V, S>where
    K: Sync,
    S: Sync,
    V: Sync,

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impl<'a, K, V, S> Unpin for RawEntryMut<'a, K, V, S>

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impl<'a, K, V, S> !UnwindSafe for RawEntryMut<'a, K, V, S>

Blanket Implementations§

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impl<T> Any for Twhere
    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> Borrow<T> for Twhere
    T: ?Sized,

const: unstable · source§

fn borrow(&self) -> &T

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

const: unstable · source§

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

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

const: unstable · source§

fn from(t: T) -> T

Returns the argument unchanged.

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impl<T, U> Into<U> for Twhere
    U: From<T>,

const: unstable · source§

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> TryFrom<U> for Twhere
    U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
const: unstable · source§

fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<T, U> TryInto<U> for Twhere
    U: TryFrom<T>,

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

The type returned in the event of a conversion error.
const: unstable · source§

fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.