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References: <b54801cd-1afb-2190-3b8a-4a095d04fdff@gmail.com> <20230523110709.4077557-1-aliceryhl@google.com>
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From:   Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Date:   Tue, 30 May 2023 16:13:47 +0200
Message-ID: <CANiq72kw-3usvn6JfD9Lp5KVrYyCVgOEehM7qXdpTvoDrX5TCw@mail.gmail.com>
Subject: Re: [PATCH v1 6/7] rust: workqueue: add safe API to workqueue
To:     Alice Ryhl <aliceryhl@google.com>
Cc:     yakoyoku@gmail.com, alex.gaynor@gmail.com, benno.lossin@proton.me,
        bjorn3_gh@protonmail.com, boqun.feng@gmail.com, gary@garyguo.net,
        jiangshanlai@gmail.com, linux-kernel@vger.kernel.org,
        ojeda@kernel.org, patches@lists.linux.dev,
        rust-for-linux@vger.kernel.org, tj@kernel.org, wedsonaf@gmail.com
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On Tue, May 23, 2023 at 1:07=E2=80=AFPM Alice Ryhl <aliceryhl@google.com> w=
rote:
>
> I think this is a question of style. For a comparison:
>
> match (queue_work_on)(work_ptr) {
>     true =3D> Ok(()),
>     // SAFETY: The work queue has not taken ownership of the pointer.
>     false =3D> Err(unsafe { Arc::from_raw(ptr) }),
> }
>
> vs
>
> if (queue_work_on)(work_ptr) {
>     Ok(())
> } else {
>     // SAFETY: The work queue has not taken ownership of the pointer.
>     Err(unsafe { Arc::from_raw(ptr) }),
> }

There is also the possibility of using the early return style:

    if ... {
        return Err(...);
    }

    Ok(())

This one makes it consistent with other early exits (i.e. whether at
the end of the function or not) and closer to the C side.

It is particularly nice when we are talking about errors, instead of
two "equal", non-error outcomes.

Cheers,
Miguel