Re: [PATCH v8] rust: add new macro for common bitflag operations

[Andreas Hindborg <a.hindborg@kernel.org>]

"Filipe Xavier" <felipeaggger@gmail.com> writes:

> 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@collabora.com>
> Suggested-by: Lyude Paul <lyude@redhat.com>
> Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
> Reviewed-by: Lyude Paul <lyude@redhat.com>
> Signed-off-by: Filipe Xavier <felipeaggger@gmail.com>

Tested-by: Andreas Hindborg <a.hindborg@kernel.org>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>


I think it would be useful to add:

impl Flags {
     unsafe from_raw(value: Repr) -> {
     ...
     }
}

impl TryFrom<Repr> for Flag {
     // Succeed if `value` is a valid `Flag` enum bit pattern.
}

impl TryFrom<Repr> for Flags {
     // Succeed if `value` is the logical OR of valid enum bit patterns.
}



Best regards,
Andreas Hindborg