Trait ReadPlace 

pub unsafe trait ReadPlace: PlaceHandle {
    const ACCESS: AccessKind;
    const SAFE: bool;

    // Required method
    unsafe fn read_place(self) -> Self::Target;
}

let _ = place; – Read from a place.

Reading from a place doesn’t have any special syntax, instead a read can happens in many places. This occurs precisely when a place expression is used in a value context¹. For example:

• let _ = place;
• match place { /* ... */ }
• function(place)

When a place expression is being read, its handle must implement this trait. Additionally, the type stored in the place must be Copy, or the handle must also implement MovePlace. Otherwise a compiler error will be emitted that the value cannot be moved out.

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1. https://doc.rust-lang.org/nightly/reference/expressions.html#r-expr.move ↩

Required Associated Constants

const ACCESS: AccessKind

The access permissions to the place required by Self::read_place.

const SAFE: bool

Whether Self::read_place is safe when Self::ACCESS is honored.

This constant controls whether the compiler will require writing an unsafe block around reading from a place that uses this handle.

Required Methods

unsafe fn read_place(self) -> Self::Target

Read from the place.

Safety

This handle must have Self::ACCESS permissions for the duration of this method call.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementations on Foreign Types

impl<T> ReadPlace for *const T

const ACCESS: AccessKind = AccessKind::Untracked

const SAFE: bool = false

unsafe fn read_place(self) -> Self::Target

impl<T> ReadPlace for *mut T

const ACCESS: AccessKind = AccessKind::Untracked

const SAFE: bool = false

unsafe fn read_place(self) -> Self::Target

impl<T> ReadPlace for NonNull<T>

const ACCESS: AccessKind = AccessKind::Exclusive

const SAFE: bool = false

unsafe fn read_place(self) -> Self::Target

Implementors

impl<'a, T> ReadPlace for RefHandle<'a, T>

const ACCESS: AccessKind = AccessKind::Shared

const SAFE: bool = true

impl<H> ReadPlace for PinnedHandle<H>

where H: ReadPlace, H::Target: Sized + Unpin,

const ACCESS: AccessKind = H::ACCESS

const SAFE: bool = H::SAFE

impl<T> ReadPlace for ArcRefHandle<T>

const ACCESS: AccessKind = AccessKind::Shared

const SAFE: bool = true

impl<T> ReadPlace for BoxHandle<T>

const ACCESS: AccessKind = AccessKind::Shared

const SAFE: bool = true

impl<T> ReadPlace for LocalHandle<T>

const ACCESS: AccessKind = AccessKind::Shared

const SAFE: bool = true

impl<T> ReadPlace for MutHandle<'_, T>

const ACCESS: AccessKind = AccessKind::Exclusive

const SAFE: bool = true