Type Alias ArcSwapOption

pub type ArcSwapOption<T> = ArcSwapAny<Option<Arc<T>>>;

An atomic storage for Option<Arc>.

This is very similar to ArcSwap, but allows storing NULL values, which is useful in some situations.

This is a type alias only. Most of the methods are described on ArcSwapAny. Even though the examples there often use ArcSwap, they are applicable to ArcSwapOption with appropriate changes.

Examples

use std::sync::Arc;
use arc_swap::ArcSwapOption;

let shared = ArcSwapOption::from(None);
assert!(shared.load_full().is_none());
assert!(shared.swap(Some(Arc::new(42))).is_none());
assert_eq!(42, **shared.load_full().as_ref().unwrap());

Aliased Type

struct ArcSwapOption<T> { /* private fields */ }

Implementations

impl<T> ArcSwapOption<T>

pub const fn const_empty() -> Self

A const-fn equivalent of empty.

Just like empty, this creates an None-holding ArcSwapOption. The empty is, however, more general ‒ this is available only for the default strategy, while empty is for any Default-constructible strategy (current or future one).

Examples

static GLOBAL_DATA: ArcSwapOption<usize> = ArcSwapOption::const_empty();

assert!(GLOBAL_DATA.load().is_none());
GLOBAL_DATA.store(Some(Arc::new(42)));
assert_eq!(42, **GLOBAL_DATA.load().as_ref().unwrap());

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 8 bytes