Re: [PATCH 1/2] rust: impl_flags: add conversion functions

[Miguel Ojeda]

On Sun, Feb 15, 2026 at 9:23 PM Andreas Hindborg <a.hindborg@xxxxxxxxxx> wrote:
>
> +        impl ::core::convert::From<$flag> for $ty {
> +            #[inline]
> +            fn from(value: $flag) -> Self {
> +                // SAFETY: All `$flag` values are valid for use as `$ty`.
> +                unsafe { core::mem::transmute::<$flag, $ty>(value) }
> +            }
> +        }

Why do we need the transmute instead of a cast? Did you notice a difference?

Same in the other one -- why not constructing the object normally?

Also, you can use `Self` for `$ty` and `$flags` to make it easier to read.

In addition, I would suggest an early return with a simple `if`.

Finally, it wouldn't hurt adding a one-liner example for each at the top.

Thanks!

Cheers,
Miguel