Struct shared_rc::sync::Weak

pub struct Weak<T: ?Sized, Owner: ?Sized = dyn Destruct> { /* private fields */ }

A projecting version of Weak which allows owning a containing struct but referencing a field.

Implementations

impl<'a, T: 'a> Weak<T, dyn Destruct + 'a>

pub fn new() -> Self

Constructs a new Weak<T>

impl<'a, T: ?Sized, Owner: 'a + Sized> Weak<T, Owner>

pub fn erase_owner(this: Self) -> Weak<T, dyn Destruct + 'a>

impl<T: ?Sized, Owner: ?Sized> Weak<T, Owner>

pub fn as_ptr(&self) -> *const T

Returns a raw pointer to the object T pointed to by this Weak<T>.

The pointer is valid only if there are some strong references. The pointer may be dangling, unaligned, or even null otherwise.

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

Attempts to upgrade the Weak pointer to Arc<T>.

Returns None if no strong references exist.

pub fn owner(this: &Self) -> Weak<Owner>

Gets a reference to the owning allocation.

pub fn into_owner(this: Self) -> Weak<Owner>

Consumes this projected field, returning the owning allocation.

pub fn project<U: Sized>(
    this: Self,
    projection: impl FnOnce(&T) -> &U
) -> Weak<U, Owner>

Projects this allocation to a field.

If no strong references exist, the closure will not be called.

pub fn ptr_eq(lhs: &Self, rhs: &Self) -> bool

Returns true if the two Weaks point to the same allocation (similar to ptr::eq), or if both don’t point to any allocation (because they were crated with Weak::new()).

impl<T: ?Sized, Owner: ?Sized> Weak<T, Owner>

pub fn unsize<U: ?Sized, F>(
    this: Self,
    with: Coercion<T, U, F>
) -> Weak<U, Owner>where
    T: Sized,
    F: FnOnce(*const T) -> *const U,

Available on crate feature unsize only.

Convert this pointer with an unsizing coercion (e.g. from T to dyn Trait or [T; N] to [T]).

pub fn unsize_owner<Pwner: ?Sized, F>(
    this: Self,
    with: Coercion<Owner, Pwner, F>
) -> Weak<T, Pwner>where
    Owner: Sized,
    F: FnOnce(*const Owner) -> *const Pwner,

Available on crate feature unsize only.

Convert this pointer with an unsizing coercion of the owner (e.g. from T to dyn Trait or [T; N] to [T]).

Trait Implementations

impl<T: Clone + ?Sized, Owner: Clone + ?Sized> Clone for Weak<T, Owner>

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

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<T, U: ?Sized, Owner: ?Sized> CoerciblePtr<U> for Weak<T, Owner>

Available on crate feature unsize only.

type Pointee = T

The type we point to. This influences which kinds of unsizing are possible.

type Output = Weak<U, Owner>

The output type when unsizing the pointee to U.

fn as_sized_ptr(&mut self) -> *mut Self::Pointee

Get the raw inner pointer.

unsafe fn replace_ptr(self, ptr: *mut U) -> Self::Output

Replace the container inner pointer with an unsized version.

impl<T: ?Sized, Owner: ?Sized> Debug for Weak<T, Owner>where
    T: Debug,

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

Formats the value using the given formatter.

impl<T, Owner: ?Sized> Default for Weak<T, Owner>where
    Weak<T, Owner>: From<Weak<T, T>>,

fn default() -> Self

Returns the “default value” for a type.

impl<'a, T: ?Sized, Owner: 'a> From<Weak<T, Owner>> for Weak<T, dyn Destruct + 'a>

fn from(this: Weak<T, Owner>) -> Self

Converts to this type from the input type.

impl<T: ?Sized, Owner: ?Sized> Send for Weak<T, Owner>where
    Weak<T>: Send,

impl<T: ?Sized, Owner: ?Sized> Sync for Weak<T, Owner>where
    Weak<T>: Sync,

impl<T: ?Sized, Owner: ?Sized> UnwindSafe for Weak<T, Owner>where
    for<'a> &'a T: UnwindSafe,
    Weak<Owner>: UnwindSafe,

Available on crate feature std only.