# Module alloc::arc 1.0.0 [−] [src]

Threadsafe reference-counted boxes (the `Arc<T>` type).

The `Arc<T>` type provides shared ownership of an immutable value through atomic reference counting.

`Weak<T>` is a weak reference to the `Arc<T>` box, and it is created by the `downgrade` method.

# Examples

Sharing some immutable data between threads:

    use std::sync::Arc;
    use std::thread;

    let five = Arc::new(5);

    for _ in 0..10 {
        let five = five.clone();

        thread::spawn(move || {
            println!("{:?}", five);
        });
    }

## Structs

Arc | An atomically reference counted wrapper for shared state. Destruction is deterministic, and will occur as soon as the last owner is gone. It is marked as `Send` because it uses atomic reference counting.
Weak | A weak pointer to an `Arc`.

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