Re: [PATCH v9] rust: add new macro for common bitflag operations

[Miguel Ojeda]

On Sat, Jan 17, 2026 at 11:41 AM Filipe Xavier <felipeaggger@xxxxxxxxx> wrote:
>
> We have seen a proliferation of mod_whatever::foo::Flags
> being defined with essentially the same implementation
> for BitAnd, BitOr, contains and etc.
>
> This macro aims to bring a solution for this,
> allowing to generate these methods for user-defined structs.
> With some use cases in KMS and upcoming GPU drivers.
>
> Link: https://rust-for-linux.zulipchat.com/#narrow/channel/288089-General/topic/We.20really.20need.20a.20common.20.60Flags.60.20type
> Suggested-by: Daniel Almeida <daniel.almeida@xxxxxxxxxxxxx>
> Suggested-by: Lyude Paul <lyude@xxxxxxxxxx>
> Reviewed-by: Daniel Almeida <daniel.almeida@xxxxxxxxxxxxx>
> Reviewed-by: Lyude Paul <lyude@xxxxxxxxxx>
> Tested-by: Andreas Hindborg <a.hindborg@xxxxxxxxxx>
> Reviewed-by: Andreas Hindborg <a.hindborg@xxxxxxxxxx>
> Signed-off-by: Filipe Xavier <felipeaggger@xxxxxxxxx>

So I was about to apply this one and I noticed a few bits (no need for
a new version):

  - This was added to the prelude -- I asked the team and they felt it
wasn't needed, so I will remove it. We can always add it later on if
needed.

  - Is `BitXorAssign<$flag> for $flags` missing for some reason? I will add:

        impl ::core::ops::BitXorAssign<$flag> for $flags {
            #[inline]
            fn bitxor_assign(&mut self, rhs: $flag) {
                *self = *self ^ rhs;
            }
        }

    This is why I like to have tests for every operator... I may open
a good first issue about it :)

I also fixed an intra-doc link and tweaked a couple other bits.

Cheers,
Miguel