Re: [PATCH v3] rust: optimize error type to use nonzero

[Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>]

On Sat, Oct 5, 2024 at 7:14 PM Filipe Xavier <felipe_life@live.com> wrote:
>
> Before the macro doesn't use unsafe anywhere, but now i need call a
> `NonZeroI32::new_unchecked`, i added the `build_assert!` to ensure
> that the macro is safe, and improve the safety comment.

Yeah, that is good, what I was saying is that the compiler should be
able to catch that case during CTFE (although I think it does not
guarantee it in the general case, but I don't know if it does in a
case like this). So I was curious.

> It's possible, but i don't like how it ends up with EINVAL instead of a
> compilation failure when passed an incorrect value.

Not necessarily -- you can return an `Option<Error>`, for instance,
from that new constructor.

(You may find that you want `feature(const_option)`; but you could do
it manually in a stable way too).

Cheers,
Miguel