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

A view into a vacant entry in a BTreeMap. It is part of the Entry enum.

Implementations§

source§

impl<'a, K, V, A> VacantEntry<'a, K, V, A>
where K: Ord, A: Allocator + Clone,

1.10.0 · source

pub fn key(&self) -> &K

Gets a reference to the key that would be used when inserting a value through the VacantEntry.

§Examples
use std::collections::BTreeMap;

let mut map: BTreeMap<&str, usize> = BTreeMap::new();
assert_eq!(map.entry("poneyland").key(), &"poneyland");
1.12.0 · source

pub fn into_key(self) -> K

Take ownership of the key.

§Examples
use std::collections::BTreeMap;
use std::collections::btree_map::Entry;

let mut map: BTreeMap<&str, usize> = BTreeMap::new();

if let Entry::Vacant(v) = map.entry("poneyland") {
    v.into_key();
}
source

pub fn insert(self, value: V) -> &'a mut V

Sets the value of the entry with the VacantEntry’s key, and returns a mutable reference to it.

§Examples
use std::collections::BTreeMap;
use std::collections::btree_map::Entry;

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

if let Entry::Vacant(o) = map.entry("poneyland") {
    o.insert(37);
}
assert_eq!(map["poneyland"], 37);

Trait Implementations§

1.12.0 · source§

impl<K, V, A> Debug for VacantEntry<'_, K, V, A>
where K: Debug + Ord, A: Allocator + Clone,

source§

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

Formats the value using the given formatter. Read more

Auto Trait Implementations§

§

impl<'a, K, V, A> Freeze for VacantEntry<'a, K, V, A>
where A: Freeze, K: Freeze,

§

impl<'a, K, V, A> RefUnwindSafe for VacantEntry<'a, K, V, A>

§

impl<'a, K, V, A> Send for VacantEntry<'a, K, V, A>
where A: Send, K: Send, V: Send,

§

impl<'a, K, V, A> Sync for VacantEntry<'a, K, V, A>
where A: Sync, K: Sync, V: Sync,

§

impl<'a, K, V, A> Unpin for VacantEntry<'a, K, V, A>
where A: Unpin, K: Unpin,

§

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

Blanket Implementations§

source§

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

source§

fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
source§

impl<T> Borrow<T> for T
where T: ?Sized,

source§

fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
source§

impl<T> BorrowMut<T> for T
where T: ?Sized,

source§

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

Mutably borrows from an owned value. Read more
source§

impl<T> From<T> for T

source§

fn from(t: T) -> T

Returns the argument unchanged.

source§

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

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.

source§

impl<T> IntoEither for T

source§

fn into_either(self, into_left: bool) -> Either<Self, Self>

Converts self into a Left variant of Either<Self, Self> if into_left is true. Converts self into a Right variant of Either<Self, Self> otherwise. Read more
source§

fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
where F: FnOnce(&Self) -> bool,

Converts self into a Left variant of Either<Self, Self> if into_left(&self) returns true. Converts self into a Right variant of Either<Self, Self> otherwise. Read more
source§

impl<T> Same for T

§

type Output = T

Should always be Self
source§

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

§

type Error = Infallible

The type returned in the event of a conversion error.
source§

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

Performs the conversion.
source§

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

§

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

The type returned in the event of a conversion error.
source§

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

Performs the conversion.
§

impl<V, T> VZip<V> for T
where V: MultiLane<T>,

§

fn vzip(self) -> V