Struct hashbrown::set::VacantEntry

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pub struct VacantEntry<'a, T, S, A: Allocator = Global> {
    inner: VacantEntry<'a, T, (), S, A>,
}
Expand description

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

Examples

use hashbrown::hash_set::{Entry, HashSet, VacantEntry};

let mut set = HashSet::<&str>::new();

let entry_v: VacantEntry<_, _> = match set.entry("a") {
    Entry::Vacant(view) => view,
    Entry::Occupied(_) => unreachable!(),
};
entry_v.insert();
assert!(set.contains("a") && set.len() == 1);

// Nonexistent key (insert)
match set.entry("b") {
    Entry::Vacant(view) => view.insert(),
    Entry::Occupied(_) => unreachable!(),
}
assert!(set.contains("b") && set.len() == 2);

Fields§

§inner: VacantEntry<'a, T, (), S, A>

Implementations§

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impl<'a, T, S, A: Allocator> VacantEntry<'a, T, S, A>

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pub fn get(&self) -> &T

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

Examples
use hashbrown::HashSet;

let mut set: HashSet<&str> = HashSet::new();
assert_eq!(set.entry("poneyland").get(), &"poneyland");
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pub fn into_value(self) -> T

Take ownership of the value.

Examples
use hashbrown::hash_set::{Entry, HashSet};

let mut set: HashSet<&str> = HashSet::new();

match set.entry("poneyland") {
    Entry::Occupied(_) => panic!(),
    Entry::Vacant(v) => assert_eq!(v.into_value(), "poneyland"),
}
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pub fn insert(self)where T: Hash, S: BuildHasher,

Sets the value of the entry with the VacantEntry’s value.

Examples
use hashbrown::HashSet;
use hashbrown::hash_set::Entry;

let mut set: HashSet<&str> = HashSet::new();

if let Entry::Vacant(o) = set.entry("poneyland") {
    o.insert();
}
assert!(set.contains("poneyland"));
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fn insert_entry(self) -> OccupiedEntry<'a, T, S, A>where T: Hash, S: BuildHasher,

Trait Implementations§

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impl<T: Debug, S, A: Allocator> Debug for VacantEntry<'_, T, S, A>

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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, T, S, A> RefUnwindSafe for VacantEntry<'a, T, S, A>where A: RefUnwindSafe, S: RefUnwindSafe, T: RefUnwindSafe,

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impl<'a, T, S, A> Send for VacantEntry<'a, T, S, A>where A: Send, S: Send, T: Send,

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impl<'a, T, S, A> Sync for VacantEntry<'a, T, S, A>where A: Sync, S: Sync, T: Sync,

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impl<'a, T, S, A> Unpin for VacantEntry<'a, T, S, A>where T: Unpin,

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impl<'a, T, S, A = Global> !UnwindSafe for VacantEntry<'a, T, S, A>

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,

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fn borrow(&self) -> &T

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

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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

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fn from(t: T) -> T

Returns the argument unchanged.

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

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

Performs the conversion.