Re: [PATCH] rust: impl_flags: add method to return underlying integer

[Andreas Hindborg]

Gary Guo <gary@xxxxxxxxxxx> writes:

> On 2026-02-12 16:02, Andreas Hindborg wrote:
>> Add a method to return the underlying integer used for flags. This is
>> useful when using the flags with C APIs.
>> 
>> Signed-off-by: Andreas Hindborg <a.hindborg@xxxxxxxxxx>
>
> I am not sure if we want to actually expose the underlying representation
> for all flags. It should be something up to the caller of `impl_flags` to
> decide.
>
> Would it make sense to add visibility the wrapped raw type so that you
> can do
>
> impl_flags! {
>     pub struct Foo(pub u32);
>     ...
> }
>
> to make the inner accessible?

I don't see how that is better?

                bindings::blk_mq_tag_set {
                    ...
                    flags: flags.into_inner(),
                    ...
                }

vs

                bindings::blk_mq_tag_set {
                    ...
                    flags: flags.0,
                    ...
                }


I would prefer the first one.

We are going to need to be able to pass these flags into C APIs. I feel
like adding a method to do this is the best way to go about this. We can
call it something else if that communicates the purpose better.

Best regards,
Andreas Hindborg