Re: [PATCH v5 22/24] rust: types: add `ForLt` trait for higher-ranked lifetime support

[Miguel Ojeda]

On Mon, May 25, 2026 at 10:32 PM Danilo Krummrich <dakr@xxxxxxxxxx> wrote:
>
> +/// Representation of types generic over a lifetime.
> +///
> +/// The type must be covariant over the generic lifetime, i.e. the lifetime parameter
> +/// can be soundly shortened.

I wonder if we could keep some of the commit message around here -- it
was a well-written one!

> +/// The full syntax is
> +/// ```

Nit: we are not fully consistent treewide about this, but please add a
newline before (and after) examples/code blocks.

> +/// ForLt!(TypeThatUse<'_>) // Equivalent to `ForLt!(for<'a> TypeThatUse<'a>)`

Nit: please end comments with a period (most in the patch are already OK).

> +        // https://github.com/rust-lang/rust/issues/152489

Linked to:

  https://github.com/Rust-for-Linux/linux/issues/355

and tagged the issue with our label upstream.

> +    // Currently the Rust compiler doesn't check this, see the above ProveWf documentation.

Nit: `ProveWf`

> +/// Obtain a type that implements `ForLt` for the given higher-ranked type.

Nit: [`ForLt`] like below.

> +/// Please refer to the documentation of [`ForLt`] trait.

"of the"?

> +#[allow(non_snake_case)] // The macro shares the name with the trait.

We normally put comments on top of attributes, but if somehow that
messes up the formatting or similar, please ignore it.

Acked-by: Miguel Ojeda <ojeda@xxxxxxxxxx>

Thanks!

Cheers,
Miguel