Struct Keys

pub struct Keys<'a, K: 'a, V: 'a> { pub(in ::collections::hash::map) inner: Iter<'a, K, V> }

An iterator over the keys of a HashMap.

This struct is created by the keys method on HashMap. See its documentation for more.

Example

use std::collections::HashMap;

let map = HashMap::from([
    ("a", 1),
]);
let iter_keys = map.keys();

Fields

inner: Iter<'a, K, V>

Trait Implementations

impl<'a, K, V> Iterator for Keys<'a, K, V>

type Item = &'a K;
fn next(&mut self) -> Option<&'a K>
fn size_hint(&self) -> (usize, Option<usize>)
fn count(self) -> usize
fn fold<B, F>(self, init: B, f: F) -> B
where
    Self: Sized,
    F: FnMut(B, Self::Item) -> B,

impl<K, V> Clone for Keys<'_, K, V>

fn clone(&self) -> Self

impl<K, V> Default for Keys<'_, K, V>

fn default() -> Self

impl<K, V> ExactSizeIterator for Keys<'_, K, V>

fn len(&self) -> usize

impl<K, V> FusedIterator for Keys<'_, K, V>

impl<K: Debug, V> Debug for Keys<'_, K, V>

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

Auto Trait Implementations

impl<'a, K, V> Freeze for Keys<'a, K, V> where Iter<'a, K, V>: Freeze,

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

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

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

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

impl<'a, K, V> UnsafeUnpin for Keys<'a, K, V> where Iter<'a, K, V>: UnsafeUnpin,

impl<'a, K, V> UnwindSafe for Keys<'a, K, V> where Iter<'a, K, V>: UnwindSafe,

Blanket Implementations

impl<I> IntoIterator for Keys<'a, K, V> where I: Iterator,

type Item = <I as Iterator>::Item;
type IntoIter = I;
fn into_iter(self) -> I

impl<T> Any for Keys<'a, K, V> where T: 'static + ?Sized,

fn type_id(&self) -> TypeId

impl<T> Borrow<T> for Keys<'a, K, V> where T: ?Sized,

fn borrow(&self) -> &T

impl<T> BorrowMut<T> for Keys<'a, K, V> where T: ?Sized,

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

impl<T> CloneToUninit for Keys<'a, K, V> where T: Clone,

unsafe fn clone_to_uninit(&self, dest: *mut u8)

impl<T> From<T> for Keys<'a, K, V>

fn from(t: T) -> T

Returns the argument unchanged.

impl<T> SizeHint for Keys<'a, K, V> where T: ?Sized,

fn lower_bound(&self) -> usize
fn upper_bound(&self) -> Option<usize>

impl<T> SizedTypeProperties for Keys<'a, K, V>

impl<T> ToOwned for Keys<'a, K, V> where T: Clone,

type Owned = T;
fn to_owned(&self) -> T
fn clone_into(&self, target: &mut T)

impl<T, U> Into<U> for Keys<'a, K, V> where U: From<T>,

fn into(self) -> U

Calls U::from(self).

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

impl<T, U> TryFrom<U> for Keys<'a, K, V> where U: Into<T>,

type Error = never;
fn try_from(value: U) -> Result<T, never>

impl<T, U> TryInto<U> for Keys<'a, K, V> where U: TryFrom<T>,

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