Struct scc::Accessor

pub struct Accessor<'a, K: Eq + Hash + Sync, V: Sync, H: BuildHasher> { /* fields omitted */ }

Accessor owns a key-value pair in the HashMap.

It is !Send, thus disallowing other threads to have references to it. It acquires an exclusive lock on the cell managing the key. A thread having multiple Accessor of Cursor instances poses a possibility of deadlock.

Implementations

impl<'a, K: Eq + Hash + Sync, V: Sync, H: BuildHasher> Accessor<'a, K, V, H>

pub fn get(&'a self) -> (&'a K, &'a mut V)

Returns a reference to the key-value pair.

Examples

use scc::HashMap;

let hashmap: HashMap<u64, u32, _> = Default::default();

let result = hashmap.get(&1);
assert!(result.is_none());

let result = hashmap.insert(1, 0);
if let Ok(result) = result {
    assert_eq!(result.get(), (&1, &mut 0));
    (*result.get().1) = 2;
}

let result = hashmap.get(&1);
assert_eq!(result.unwrap().get(), (&1, &mut 2));

pub fn erase(self) -> Option<V>

Erases the key-value pair owned by the Accessor.

Examples

use scc::HashMap;

let hashmap: HashMap<u64, u32, _> = Default::default();

let result = hashmap.insert(1, 0);
if let Ok(result) = result {
    assert_eq!(result.get(), (&1, &mut 0));
    let result = result.erase();
    assert_eq!(result.unwrap(), 0);
}

let result = hashmap.get(&1);
assert!(result.is_none());