Struct alloc::rc::Weak
[−]
[src]
pub struct Weak<T: ?Sized> {
// some fields omitted
}1.4.0A weak version of Rc<T>.
Weak references do not count when determining if the inner value should be dropped.
See the module level documentation for more.
Methods
impl<T: ?Sized> Weak<T>
fn upgrade(&self) -> Option<Rc<T>>
Upgrades a weak reference to a strong reference.
Upgrades the Weak<T> reference to an Rc<T>, if possible.
Returns None if there were no strong references and the data was
destroyed.
Examples
use std::rc::Rc; let five = Rc::new(5); let weak_five = Rc::downgrade(&five); let strong_five: Option<Rc<_>> = weak_five.upgrade();
impl<T> Weak<T>
fn new() -> Weak<T>
Constructs a new Weak<T> without an accompanying instance of T.
This allocates memory for T, but does not initialize it. Calling
Weak
Examples
#![feature(downgraded_weak)] use std::rc::Weak; let empty: Weak<i64> = Weak::new();