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

[Gary Guo <gary@garyguo.net>]

On Wed, 17 May 2023 20:08:14 +0000
Alice Ryhl <aliceryhl@google.com> 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@microsoft.com>
> Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com>
> Signed-off-by: Alice Ryhl <aliceryhl@google.com>

Reviewed-by: Gary Guo <gary@garyguo.net>

> ---
>  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.