Struct alloc::arc::WeakUnstable

pub struct Weak<T> {
    // some fields omitted
}

A weak pointer to an Arc.

Weak pointers will not keep the data inside of the Arc alive, and can be used to break cycles between Arc pointers.

Methods

impl<T: Sync + Send> Weak<T>

fn upgrade(&self) -> Option<Arc<T>>

Upgrades a weak reference to a strong reference.

Upgrades the Weak<T> reference to an Arc<T>, if possible.

Returns None if there were no strong references and the data was destroyed.

Examples

use std::sync::Arc;

let five = Arc::new(5);

let weak_five = five.downgrade();

let strong_five: Option<Arc<_>> = weak_five.upgrade();

Trait Implementations

impl<T: Sync + Send> Send for Weak<T>

impl<T: Sync + Send> Sync for Weak<T>

impl<T: Sync + Send> Clone for Weak<T>

fn clone(&self) -> Weak<T>

Makes a clone of the Weak<T>.

This increases the weak reference count.

Examples

use std::sync::Arc;

let weak_five = Arc::new(5).downgrade();

weak_five.clone();

fn clone_from(&mut self, source: &Self)

impl<T: Sync + Send> Drop for Weak<T>

fn drop(&mut self)

Drops the Weak<T>.

This will decrement the weak reference count.

Examples

use std::sync::Arc;

{
    let five = Arc::new(5);
    let weak_five = five.downgrade();

    // stuff

    drop(weak_five); // explicit drop
}
{
    let five = Arc::new(5);
    let weak_five = five.downgrade();

    // stuff

} // implicit drop