Struct ValueGuard

pub struct ValueGuard<T> { /* private fields */ }

Strong guard for granting read access to a single interior mutable value to RefGuard.

A ValueGuard:RefGuard relationship is exclusive, and behaves similarly to a single Rc and Weak pair, but notably does not require heap allocation. ValueGuard::registration creates a GuardRegistration, which provides a movable wrapper for safety creating the circular references between two pinned self referential structs.

Safety

This struct must not be leaked to the stack using mem::forget or any other mechanism that causes the contents of Self to be overwritten without Drop::drop() running. Doing so creates unsoundness that likely will lead to dereferencing a null pointer.

Note that it is sound to leak Self to the heap using methods including Box::leak() because heap allocated data will never be overwritten if it is never freed.

Implementations

impl<T> ValueGuard<T>

pub fn new(data: T) -> Self

Creates a new ValueGuard containing data.

pub fn registration<'a>(self: Pin<&'a Self>) -> GuardRegistration<'a, T>

Returns a GuardRegistration, which can be used to safety link Self to a RefGuard.

pub fn set(&self, value: T)

Sets the internal value stored by Self.

impl<T: Copy> ValueGuard<T>

pub fn get(&self) -> T

Gets a copy of the value stored inside this ValueGuard.

Trait Implementations

impl<T> Drop for ValueGuard<T>

fn drop(&mut self)

Executes the destructor for this type.