Struct std::rc::WeakUnstable

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

A 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> 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

fn main() { use std::rc::Rc; let five = Rc::new(5); let weak_five = five.downgrade(); let strong_five: Option<Rc<_>> = weak_five.upgrade(); }

use std::rc::Rc;

let five = Rc::new(5);

let weak_five = five.downgrade();

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

Trait Implementations

impl<T> !Send for Weak<T>

impl<T> !Sync for Weak<T>

impl<T> Drop for Weak<T>

fn drop(&mut self)

Drops the Weak<T>.

This will decrement the weak reference count.

Examples

fn main() { use std::rc::Rc; { let five = Rc::new(5); let weak_five = five.downgrade(); // stuff drop(weak_five); // explicit drop } { let five = Rc::new(5); let weak_five = five.downgrade(); // stuff } // implicit drop }

use std::rc::Rc;

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

    // stuff

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

    // stuff

} // implicit drop

impl<T> Clone for Weak<T>

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

Makes a clone of the Weak<T>.

This increases the weak reference count.

Examples

fn main() { use std::rc::Rc; let weak_five = Rc::new(5).downgrade(); weak_five.clone(); }

use std::rc::Rc;

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

weak_five.clone();

fn clone_from(&mut self, &Weak<T>)

impl<T> Debug for Weak<T> where T: Debug

fn fmt(&self, f: &mut Formatter) -> Result<(), Error>