Struct WeakPtr

pub struct WeakPtr<T: ?Sized> { /* private fields */ }

Represents a pointer that only references the data it’s pointing to. Unlike OwnedPtr, dropping this pointer has no effect on the underlying data, this pointer can only immutably access the underlying data, and care must be taken to prevent this pointer from dangling.

This can be used in conjunction with OwnedPtr to form complex (and sometimes cyclic) data structures while still adhering to Rust’s ownership rules, and avoiding un-droppable memory cycles.

Implementations

impl<T: ?Sized + 'static> WeakPtr<T>

pub fn create_uninitialized() -> Self

impl<T: ?Sized> WeakPtr<T>

pub fn is_initialized(&self) -> bool

pub fn borrow(&self) -> &T

pub fn downcast<U: 'static>(self) -> Result<WeakPtr<U>, WeakPtr<T>>

pub fn from_inner(inner: (Option<*const T>, TypeId)) -> Self

pub fn into_inner(self) -> (Option<*const T>, TypeId)

Trait Implementations

impl<T: ?Sized> Clone for WeakPtr<T>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

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

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

Formats the value using the given formatter.

impl<'a, T: ?Sized, U: ?Sized> PartialEq<&'a T> for WeakPtr<U>

fn eq(&self, other: &&'a T) -> bool

Returns true if this pointer and the provided reference both point to the same memory address.

Note that this may return true in some unintuitive/exotic cases:

• If you have 2 references to the same piece of data, with different types, this will return true. For example, comparing String to dyn Display is valid, and will return true if they’re actually the same.
• If one or both of the types are zero-sized: since it’s address may overlap with another piece of data.
• Comparing the address of a struct to the address of its first field: these are conceptually different things, but both live at the same address, since structs are stored as a list of it’s fields.

See https://doc.rust-lang.org/std/ptr/fn.eq.html for more information. This function uses the same semantics.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<'a> TryFrom<&'a Node> for WeakPtr<Attribute>

fn try_from(node: &'a Node) -> Result<WeakPtr<Attribute>, Self::Error>

Attempts to unwrap a node to the specified concrete type.

If the Slice element held by the node is the specified type, this succeeds, and returns the unwrapped element in the requested container. Otherwise this method fails and returns an error message.

type Error = LookupError

The type returned in the event of a conversion error.

impl<'a> TryFrom<&'a Node> for WeakPtr<Class>

fn try_from(node: &'a Node) -> Result<WeakPtr<Class>, Self::Error>

Attempts to unwrap a node to the specified concrete type.

If the Slice element held by the node is the specified type, this succeeds, and returns the unwrapped element in the requested container. Otherwise this method fails and returns an error message.

type Error = LookupError

The type returned in the event of a conversion error.

impl<'a> TryFrom<&'a Node> for WeakPtr<CustomType>

fn try_from(node: &'a Node) -> Result<WeakPtr<CustomType>, Self::Error>

Attempts to unwrap a node to the specified concrete type.

If the Slice element held by the node is the specified type, this succeeds, and returns the unwrapped element in the requested container. Otherwise this method fails and returns an error message.

type Error = LookupError

The type returned in the event of a conversion error.

impl<'a> TryFrom<&'a Node> for WeakPtr<Dictionary>

fn try_from(node: &'a Node) -> Result<WeakPtr<Dictionary>, Self::Error>

Attempts to unwrap a node to the specified concrete type.

If the Slice element held by the node is the specified type, this succeeds, and returns the unwrapped element in the requested container. Otherwise this method fails and returns an error message.

type Error = LookupError

The type returned in the event of a conversion error.

impl<'a> TryFrom<&'a Node> for WeakPtr<Enum>

fn try_from(node: &'a Node) -> Result<WeakPtr<Enum>, Self::Error>

Attempts to unwrap a node to the specified concrete type.

If the Slice element held by the node is the specified type, this succeeds, and returns the unwrapped element in the requested container. Otherwise this method fails and returns an error message.

type Error = LookupError

The type returned in the event of a conversion error.

impl<'a> TryFrom<&'a Node> for WeakPtr<Enumerator>

fn try_from(node: &'a Node) -> Result<WeakPtr<Enumerator>, Self::Error>

Attempts to unwrap a node to the specified concrete type.

If the Slice element held by the node is the specified type, this succeeds, and returns the unwrapped element in the requested container. Otherwise this method fails and returns an error message.

type Error = LookupError

The type returned in the event of a conversion error.

impl<'a> TryFrom<&'a Node> for WeakPtr<Exception>

fn try_from(node: &'a Node) -> Result<WeakPtr<Exception>, Self::Error>

Attempts to unwrap a node to the specified concrete type.

If the Slice element held by the node is the specified type, this succeeds, and returns the unwrapped element in the requested container. Otherwise this method fails and returns an error message.

type Error = LookupError

The type returned in the event of a conversion error.

impl<'a> TryFrom<&'a Node> for WeakPtr<Field>

fn try_from(node: &'a Node) -> Result<WeakPtr<Field>, Self::Error>

Attempts to unwrap a node to the specified concrete type.

If the Slice element held by the node is the specified type, this succeeds, and returns the unwrapped element in the requested container. Otherwise this method fails and returns an error message.

type Error = LookupError

The type returned in the event of a conversion error.

impl<'a> TryFrom<&'a Node> for WeakPtr<Interface>

fn try_from(node: &'a Node) -> Result<WeakPtr<Interface>, Self::Error>

Attempts to unwrap a node to the specified concrete type.

If the Slice element held by the node is the specified type, this succeeds, and returns the unwrapped element in the requested container. Otherwise this method fails and returns an error message.

type Error = LookupError

The type returned in the event of a conversion error.

impl<'a> TryFrom<&'a Node> for WeakPtr<Module>

fn try_from(node: &'a Node) -> Result<WeakPtr<Module>, Self::Error>

Attempts to unwrap a node to the specified concrete type.

If the Slice element held by the node is the specified type, this succeeds, and returns the unwrapped element in the requested container. Otherwise this method fails and returns an error message.

type Error = LookupError

The type returned in the event of a conversion error.

impl<'a> TryFrom<&'a Node> for WeakPtr<Operation>

fn try_from(node: &'a Node) -> Result<WeakPtr<Operation>, Self::Error>

Attempts to unwrap a node to the specified concrete type.

If the Slice element held by the node is the specified type, this succeeds, and returns the unwrapped element in the requested container. Otherwise this method fails and returns an error message.

type Error = LookupError

The type returned in the event of a conversion error.

impl<'a> TryFrom<&'a Node> for WeakPtr<Parameter>

fn try_from(node: &'a Node) -> Result<WeakPtr<Parameter>, Self::Error>

Attempts to unwrap a node to the specified concrete type.

If the Slice element held by the node is the specified type, this succeeds, and returns the unwrapped element in the requested container. Otherwise this method fails and returns an error message.

type Error = LookupError

The type returned in the event of a conversion error.

impl<'a> TryFrom<&'a Node> for WeakPtr<Primitive>

fn try_from(node: &'a Node) -> Result<WeakPtr<Primitive>, Self::Error>

Attempts to unwrap a node to the specified concrete type.

If the Slice element held by the node is the specified type, this succeeds, and returns the unwrapped element in the requested container. Otherwise this method fails and returns an error message.

type Error = LookupError

The type returned in the event of a conversion error.

impl<'a> TryFrom<&'a Node> for WeakPtr<ResultType>

fn try_from(node: &'a Node) -> Result<WeakPtr<ResultType>, Self::Error>

Attempts to unwrap a node to the specified concrete type.

If the Slice element held by the node is the specified type, this succeeds, and returns the unwrapped element in the requested container. Otherwise this method fails and returns an error message.

type Error = LookupError

The type returned in the event of a conversion error.

impl<'a> TryFrom<&'a Node> for WeakPtr<Sequence>

fn try_from(node: &'a Node) -> Result<WeakPtr<Sequence>, Self::Error>

Attempts to unwrap a node to the specified concrete type.

If the Slice element held by the node is the specified type, this succeeds, and returns the unwrapped element in the requested container. Otherwise this method fails and returns an error message.

type Error = LookupError

The type returned in the event of a conversion error.

impl<'a> TryFrom<&'a Node> for WeakPtr<Struct>

fn try_from(node: &'a Node) -> Result<WeakPtr<Struct>, Self::Error>

Attempts to unwrap a node to the specified concrete type.

If the Slice element held by the node is the specified type, this succeeds, and returns the unwrapped element in the requested container. Otherwise this method fails and returns an error message.

type Error = LookupError

The type returned in the event of a conversion error.

impl<'a> TryFrom<&'a Node> for WeakPtr<TypeAlias>

fn try_from(node: &'a Node) -> Result<WeakPtr<TypeAlias>, Self::Error>

Attempts to unwrap a node to the specified concrete type.

If the Slice element held by the node is the specified type, this succeeds, and returns the unwrapped element in the requested container. Otherwise this method fails and returns an error message.

type Error = LookupError

The type returned in the event of a conversion error.

impl<'a> TryFrom<&'a Node> for WeakPtr<dyn Entity>

fn try_from(node: &'a Node) -> Result<WeakPtr<dyn Entity>, Self::Error>

Attempts to unwrap a node to a WeakPtr of a Slice Entity.

If the Slice element held by the node implements Entity, this succeeds and returns a typed pointer, otherwise this fails and returns an error message.

type Error = LookupError

The type returned in the event of a conversion error.

impl<'a> TryFrom<&'a Node> for WeakPtr<dyn Type>

fn try_from(node: &'a Node) -> Result<WeakPtr<dyn Type>, Self::Error>

Attempts to unwrap a node to a WeakPtr of a Slice Type.

If the Slice element held by the node implements Type, this succeeds and returns a typed pointer, otherwise this fails and returns an error message.

type Error = LookupError

The type returned in the event of a conversion error.

impl<T: ?Sized + Send> Send for WeakPtr<T>

impl<T: ?Sized + Sync> Sync for WeakPtr<T>