[PATCH v5 05/23] rust: num: add the `fls` operation

[Alexandre Courbot]

On Sun Jun 15, 2025 at 10:25 PM JST, Miguel Ojeda wrote:
> On Sun, Jun 15, 2025 at 12:58 PM Alexandre Courbot <acourbot at nvidia.com> wrote:
>>
>> Also, although this will work nicely for `impl_fls!` which is a single
>> function, I'm afraid this won't scale well for `power_of_two_impl!`,
>> which defines 6 functions per type... Any suggestions for this case?
>
> We can always generate the same "cases", i.e. sharing as much as
> possible the lines, and just passing the values (numbers) that
> actually differ, which you then plug into the example line
> concatenating.
>
> The standard library does that for their integer macros, e.g.
>
>     https://doc.rust-lang.org/src/core/num/int_macros.rs.html#3639-3644
>
> If that happened to be too onerous for some reason, then we could
> ignore it for the time being (i.e. we don't need to delay things just
> for that), or we could put them as `#[test]`s to at least have them as
> tests.

Thanks, this appears to work quite nicely (if a bit verbose), and I can
adjust the tests to avoid the need to take extra arguments.