Trait Pointable

trait Pointable

Types that are pointed to by a single word.

In concurrent programming, it is necessary to represent an object within a word because atomic operations (e.g., reads, writes, read-modify-writes) support only single words. This trait qualifies such types that are pointed to by a single word.

The trait generalizes Box<T> for a sized type T. In a box, an object of type T is allocated in heap and it is owned by a single-word pointer. This trait is also implemented for [MaybeUninit<T>] by storing its size along with its elements and pointing to the pair of array size and elements.

Pointers to Pointable types can be stored in Atomic, Owned, and Shared. In particular, Crossbeam supports dynamically sized slices as follows.

use std::mem::MaybeUninit;
use crossbeam_epoch::Owned;

let o = Owned::<[MaybeUninit<i32>]>::init(10); // allocating [i32; 10]

Associated Types

type Init

The type for initializers.

Required Methods

unsafe fn init(init: <Self as >::Init) -> usize

Initializes a with the given initializer.

Safety

The result should be a multiple of ALIGN.

unsafe fn deref<'a>(ptr: usize) -> &'a Self

Dereferences the given pointer.

Safety

unsafe fn deref_mut<'a>(ptr: usize) -> &'a mut Self

Mutably dereferences the given pointer.

Safety

unsafe fn drop(ptr: usize)

Drops the object pointed to by the given pointer.

Safety

Implementors