Re: [PATCH v8 10/14] rust: alloc: add `Box::into_pin`

[Benno Lossin]

On 18.02.25 14:27, Andreas Hindborg wrote:
> Add an associated function to convert a `Box<T>` into a `Pin<Box<T>>`.

Why don't you use `into()` directly where you need it? Do you want the
function call to be more descriptive?
(To be clear, I'm not against the addition, just wanting to check if our
motivation is the same)

> Acked-by: Danilo Krummrich <dakr@xxxxxxxxxx>
> Signed-off-by: Andreas Hindborg <a.hindborg@xxxxxxxxxx>

Reviewed-by: Benno Lossin <benno.lossin@xxxxxxxxx>

---
Cheers,
Benno

> ---
>  rust/kernel/alloc/kbox.rs | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/rust/kernel/alloc/kbox.rs b/rust/kernel/alloc/kbox.rs
> index cb4ebea3b0742..9da4a32e60bc3 100644
> --- a/rust/kernel/alloc/kbox.rs
> +++ b/rust/kernel/alloc/kbox.rs
> @@ -245,6 +245,12 @@ pub fn pin(x: T, flags: Flags) -> Result<Pin<Box<T, A>>, AllocError>
>          Ok(Self::new(x, flags)?.into())
>      }
> 
> +    /// Convert a [`Box<T,A>`] to a [`Pin<Box<T,A>>`]. If `T` does not implement
> +    /// [`Unpin`], then `x` will be pinned in memory and can't be moved.
> +    pub fn into_pin(this: Self) -> Pin<Self> {
> +        this.into()
> +    }
> +
>      /// Forgets the contents (does not run the destructor), but keeps the allocation.
>      fn forget_contents(this: Self) -> Box<MaybeUninit<T>, A> {
>          let ptr = Self::into_raw(this);
> 
> --
> 2.47.0
> 
>