1.0.0[−][src]Struct alloc::collections::btree_map::VacantEntry
A view into a vacant entry in a BTreeMap
.
It is part of the Entry
enum.
Methods
impl<'a, K: Ord, V> VacantEntry<'a, K, V>
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pub fn key(&self) -> &K
1.10.0[src]
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");
pub fn into_key(self) -> K
1.12.0[src]
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(); }
pub fn insert(self, value: V) -> &'a mut V
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Sets the value of the entry with the VacantEntry
's key,
and returns a mutable reference to it.
Examples
use std::collections::BTreeMap; let mut count: BTreeMap<&str, usize> = BTreeMap::new(); // count the number of occurrences of letters in the vec for x in vec!["a","b","a","c","a","b"] { *count.entry(x).or_insert(0) += 1; } assert_eq!(count["a"], 3);
Trait Implementations
impl<'_, K: Debug + Ord, V> Debug for VacantEntry<'_, K, V>
1.12.0[src]
Auto Trait Implementations
impl<'a, K, V> Send for VacantEntry<'a, K, V> where
K: Send,
V: Send,
K: Send,
V: Send,
impl<'a, K, V> Sync for VacantEntry<'a, K, V> where
K: Sync,
V: Sync,
K: Sync,
V: Sync,
Blanket Implementations
impl<T, U> TryFrom<U> for T where
U: Into<T>,
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U: Into<T>,
type Error = Infallible
The type returned in the event of a conversion error.
fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>
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impl<T, U> Into<U> for T where
U: From<T>,
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U: From<T>,
impl<T> From<T> for T
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impl<T, U> TryInto<U> for T where
U: TryFrom<T>,
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U: TryFrom<T>,
type Error = <U as TryFrom<T>>::Error
The type returned in the event of a conversion error.
fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>
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impl<T> Borrow<T> for T where
T: ?Sized,
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T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
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T: ?Sized,
fn borrow_mut(&mut self) -> &mut T
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impl<T> Any for T where
T: 'static + ?Sized,
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T: 'static + ?Sized,