Re: [PATCH 0/4] rust: add `TryFrom` and `Into` derive macros

["Alexandre Courbot" <acourbot@nvidia.com>]

On Sun Aug 3, 2025 at 11:20 PM JST, Jesung Yang wrote:
> This patch series introduces derive macros for `TryFrom` and `Into`
> traits.
>
> A few enhancements were made to the custom `quote!()` macro to write
> the derive macro. These include support for additional punctuation
> tokens and a fix for an unused variable warning when quoting simple
> forms. Detailed information about these enhancements is provided in the
> relevant patches.
>
> This series builds on the previous work [1], where the `FromPrimitive`
> trait was considered too heavy for the current use cases. In response
> to the emerging need for functionality similar to `ToPrimitive`, this
> series also implements the `Into` derive macro.
>
> The original discussion can be found on Zulip [2].
>
> [1] https://lore.kernel.org/rust-for-linux/cover.1750689857.git.y.j3ms.n@gmail.com/
> [2] https://rust-for-linux.zulipchat.com/#narrow/channel/288089/topic/x/near/524335626

I have tried this series on nova-core and it allowed me to remove 150
lines of boiletplate just like that. As far as nova-core is concerned,
this is a perfect fit.

For the larger kernel, where using the right type is essential and where
we want to avoid error paths whenever possible, I also feel like this is
a much better fit than the initial `FromPrimitive`. But it would be nice
to hear other opinions on the matter.

I will try to review as much as my proc-macro knowledge allows me to,
but for now:

Tested-by: Alexandre Courbot <acourbot@nvidia.com>