Struct hashbrown::hash_map::OccupiedError
source · [−]pub struct OccupiedError<'a, K, V, S, A: Allocator + Clone = Global> {
pub entry: OccupiedEntry<'a, K, V, S, A>,
pub value: V,
}
Expand description
The error returned by try_insert
when the key already exists.
Contains the occupied entry, and the value that was not inserted.
Examples
use hashbrown::hash_map::{HashMap, OccupiedError};
let mut map: HashMap<_, _> = [("a", 10), ("b", 20)].into();
// try_insert method returns mutable reference to the value if keys are vacant,
// but if the map did have key present, nothing is updated, and the provided
// value is returned inside `Err(_)` variant
match map.try_insert("a", 100) {
Err(OccupiedError { mut entry, value }) => {
assert_eq!(entry.key(), &"a");
assert_eq!(value, 100);
assert_eq!(entry.insert(100), 10)
}
_ => unreachable!(),
}
assert_eq!(map[&"a"], 100);
Fields
entry: OccupiedEntry<'a, K, V, S, A>
The entry in the map that was already occupied.
value: V
The value which was not inserted, because the entry was already occupied.
Trait Implementations
Auto Trait Implementations
impl<'a, K, V, S, A> RefUnwindSafe for OccupiedError<'a, K, V, S, A> where
A: RefUnwindSafe,
K: RefUnwindSafe,
S: RefUnwindSafe,
V: RefUnwindSafe,
impl<'a, K, V, S, A> Send for OccupiedError<'a, K, V, S, A> where
A: Send,
K: Send,
S: Send,
V: Send,
impl<'a, K, V, S, A> Sync for OccupiedError<'a, K, V, S, A> where
A: Sync,
K: Sync,
S: Sync,
V: Sync,
impl<'a, K, V, S, A> Unpin for OccupiedError<'a, K, V, S, A> where
K: Unpin,
V: Unpin,
impl<'a, K, V, S, A = Global> !UnwindSafe for OccupiedError<'a, K, V, S, A>
Blanket Implementations
sourceimpl<T> BorrowMut<T> for T where
T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
const: unstable · sourcefn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more