Re: [PATCH v3 1/4] rust: add num module and Integer trait

[Alice Ryhl <aliceryhl@google.com>]

On Thu, Nov 06, 2025 at 04:07:13PM +0900, Alexandre Courbot wrote:
> Introduce the `num` module, which will provide numerical extensions and
> utilities for the kernel.
> 
> For now, introduce the `Integer` trait, which is implemented for all
> primitive integer types to provides their core properties to generic
> code.
> 
> Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
> ---
>  rust/kernel/lib.rs |  1 +
>  rust/kernel/num.rs | 76 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 77 insertions(+)
> 
> diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
> index 3dd7bebe7888..235d0d8b1eff 100644
> --- a/rust/kernel/lib.rs
> +++ b/rust/kernel/lib.rs
> @@ -109,6 +109,7 @@
>  pub mod mm;
>  #[cfg(CONFIG_NET)]
>  pub mod net;
> +pub mod num;
>  pub mod of;
>  #[cfg(CONFIG_PM_OPP)]
>  pub mod opp;
> diff --git a/rust/kernel/num.rs b/rust/kernel/num.rs
> new file mode 100644
> index 000000000000..3f85e50b8632
> --- /dev/null
> +++ b/rust/kernel/num.rs
> @@ -0,0 +1,76 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +//! Additional numerical features for the kernel.
> +
> +use core::ops;
> +
> +/// Designates unsigned primitive types.
> +pub struct Unsigned(());
> +
> +/// Designates signed primitive types.
> +pub struct Signed(());

Since these types are not intended to be constructed, I would suggest
using enums so that they can't be constructed:

	pub enum Unsigned {}
	pub enum Signed {}

Alice