Struct alloc::arc::Weak
[−]
[src]
pub struct Weak<T: ?Sized> { // some fields omitted }
: Weak pointers may not belong in this module.
A weak pointer to an Arc
`Arc`.
Weak pointers will not keep the data inside of the Arc
`Arcalive, and can be used to break cycles between
Arc` pointers.
Methods
impl<T: ?Sized> Weak<T>
fn upgrade(&self) -> Option<Arc<T>>
: Weak pointers may not belong in this module.
Upgrades a weak reference to a strong reference.
Upgrades the Weak<T>
`Weakreference to an
Arc
Returns None
`None` if there were no strong references and the data was
destroyed.
Examples
#![feature(arc_weak)] use std::sync::Arc; let five = Arc::new(5); let weak_five = five.downgrade(); let strong_five: Option<Arc<_>> = weak_five.upgrade();