Re: [PATCH v1 2/2] rust: sync: implement `AsRef<T>` for `Arc<T>`

From: Gary Guo
Date: Tue May 23 2023 - 12:01:26 EST


On Wed, 17 May 2023 20:08:14 +0000
Alice Ryhl <aliceryhl@xxxxxxxxxx> wrote:

> This trait lets you use `Arc<T>` in code that is generic over smart
> pointer types.
>
> The `AsRef` trait should be implemented on all smart pointers. The
> standard library also implements it on the ordinary `Arc`.
>
> Co-developed-by: Wedson Almeida Filho <walmeida@xxxxxxxxxxxxx>
> Signed-off-by: Wedson Almeida Filho <walmeida@xxxxxxxxxxxxx>
> Signed-off-by: Alice Ryhl <aliceryhl@xxxxxxxxxx>

Reviewed-by: Gary Guo <gary@xxxxxxxxxxx>

> ---
> rust/kernel/sync/arc.rs | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/rust/kernel/sync/arc.rs b/rust/kernel/sync/arc.rs
> index 274febe3bb06..9ec911e4a0c7 100644
> --- a/rust/kernel/sync/arc.rs
> +++ b/rust/kernel/sync/arc.rs
> @@ -264,6 +264,12 @@ impl<T: ?Sized> Deref for Arc<T> {
> }
> }
>
> +impl<T: ?Sized> AsRef<T> for Arc<T> {
> + fn as_ref(&self) -> &T {
> + self.deref()
> + }
> +}
> +
> impl<T: ?Sized> Clone for Arc<T> {
> fn clone(&self) -> Self {
> // INVARIANT: C `refcount_inc` saturates the refcount, so it cannot overflow to zero.