Struct objc2::rc::WeakId

#[repr(transparent)]
pub struct WeakId<T: ?Sized> { /* private fields */ }

A pointer type for a weak reference to an Objective-C reference counted object.

Allows breaking reference cycles and safely checking whether the object has been deallocated.

Implementations

impl<T: Message> WeakId<T>

pub fn new(obj: &Id<T, Shared>) -> Self

Construct a new WeakId referencing the given shared Id.

pub fn load(&self) -> Option<Id<T, Shared>>

Load a shared (and retained) Id if the object still exists.

Returns None if the object has been deallocated or was created with Default::default.

Trait Implementations

impl<T> Clone for WeakId<T>

fn clone(&self) -> Self

Makes a clone of the WeakId that points to the same object.

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

Performs copy-assignment from source.

impl<T: Debug + ?Sized> Debug for WeakId<T>

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

Formats the value using the given formatter.

impl<T: Message> Default for WeakId<T>

fn default() -> Self

Constructs a new WeakId<T> that doesn’t reference any object.

Calling Self::load on the return value always gives None.

impl<T: ?Sized> Drop for WeakId<T>

fn drop(&mut self)

Drops the WeakId pointer.

impl<T: Message> From<Id<T, Shared>> for WeakId<T>

fn from(obj: Id<T, Shared>) -> Self

Converts to this type from the input type.

impl<T: Message> TryFrom<WeakId<T>> for Id<T, Shared>

type Error = ()

The type returned in the event of a conversion error.

fn try_from(weak: WeakId<T>) -> Result<Self, ()>

Performs the conversion.

impl<T: RefUnwindSafe + ?Sized> RefUnwindSafe for WeakId<T>

impl<T: Sync + Send + ?Sized> Send for WeakId<T>

This implementation follows the same reasoning as Id<T, Shared>.

impl<T: Sync + Send + ?Sized> Sync for WeakId<T>

This implementation follows the same reasoning as Id<T, Shared>.

impl<T: ?Sized> Unpin for WeakId<T>

impl<T: RefUnwindSafe + ?Sized> UnwindSafe for WeakId<T>