W3cubDocs

/Rust

Struct std::collections::hash_map::VacantEntry

pub struct VacantEntry<'a, K: 'a, V: 'a> { /* fields omitted */ }

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

Methods

impl<'a, K: 'a, V: 'a> VacantEntry<'a, K, V>[src]

pub fn key(&self) -> &K[src]1.10.0

ⓘImportant traits for &'_ mut F
impl<'_, F> Future for &'_ mut F where
    F: Unpin + Future + ?Sized, 
    type Output = <F as Future>::Output;
impl<'_, I> Iterator for &'_ mut I where
    I: Iterator + ?Sized, 
    type Item = <I as Iterator>::Item;
impl<'_, R: Read + ?Sized> Read for &'_ mut R
impl<'_, W: Write + ?Sized> Write for &'_ mut W

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

Examples

use std::collections::HashMap;

let mut map: HashMap<&str, u32> = HashMap::new();
assert_eq!(map.entry("poneyland").key(), &"poneyland");

pub fn into_key(self) -> K[src]1.12.0

Take ownership of the key.

Examples

use std::collections::HashMap;
use std::collections::hash_map::Entry;

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

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

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

ⓘImportant traits for &'_ mut F
impl<'_, F> Future for &'_ mut F where
    F: Unpin + Future + ?Sized, 
    type Output = <F as Future>::Output;
impl<'_, I> Iterator for &'_ mut I where
    I: Iterator + ?Sized, 
    type Item = <I as Iterator>::Item;
impl<'_, R: Read + ?Sized> Read for &'_ mut R
impl<'_, W: Write + ?Sized> Write for &'_ mut W

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

Examples

use std::collections::HashMap;
use std::collections::hash_map::Entry;

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

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

Trait Implementations

impl<'_, K: Debug, V> Debug for VacantEntry<'_, K, V>[src]1.12.0

Auto Trait Implementations

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

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

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

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

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

Blanket Implementations

impl<T, U> TryFrom<U> for T where
    U: Into<T>, 
[src]

type Error = Infallible

The type returned in the event of a conversion error.

impl<T, U> Into<U> for T where
    U: From<T>, 
[src]

impl<T> From<T> for T[src]

impl<T, U> TryInto<U> for T where
    U: TryFrom<T>, 
[src]

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

The type returned in the event of a conversion error.

impl<T> Borrow<T> for T where
    T: ?Sized
[src]

ⓘImportant traits for &'_ mut F
impl<'_, F> Future for &'_ mut F where
    F: Unpin + Future + ?Sized, 
    type Output = <F as Future>::Output;
impl<'_, I> Iterator for &'_ mut I where
    I: Iterator + ?Sized, 
    type Item = <I as Iterator>::Item;
impl<'_, R: Read + ?Sized> Read for &'_ mut R
impl<'_, W: Write + ?Sized> Write for &'_ mut W

impl<T> BorrowMut<T> for T where
    T: ?Sized
[src]

ⓘImportant traits for &'_ mut F
impl<'_, F> Future for &'_ mut F where
    F: Unpin + Future + ?Sized, 
    type Output = <F as Future>::Output;
impl<'_, I> Iterator for &'_ mut I where
    I: Iterator + ?Sized, 
    type Item = <I as Iterator>::Item;
impl<'_, R: Read + ?Sized> Read for &'_ mut R
impl<'_, W: Write + ?Sized> Write for &'_ mut W

impl<T> Any for T where
    T: 'static + ?Sized
[src]

© 2010 The Rust Project Developers
Licensed under the Apache License, Version 2.0 or the MIT license, at your option.
https://doc.rust-lang.org/std/collections/hash_map/struct.VacantEntry.html