From: Benno Lossin <benno.lossin@proton.me>
To: Gary Guo <gary@garyguo.net>
Cc: "Alice Ryhl" <aliceryhl@google.com>,
rust-for-linux@vger.kernel.org, "Miguel Ojeda" <ojeda@kernel.org>,
"Wedson Almeida Filho" <wedsonaf@gmail.com>,
"Alex Gaynor" <alex.gaynor@gmail.com>,
"Boqun Feng" <boqun.feng@gmail.com>,
"Björn Roy Baron" <bjorn3_gh@protonmail.com>,
linux-kernel@vger.kernel.org, patches@lists.linux.dev
Subject: Re: [PATCH] rust: make `UnsafeCell` the outer type in `Opaque`
Date: Wed, 14 Jun 2023 19:04:52 +0000 [thread overview]
Message-ID: <-MHKDYSM29ri6c9QKvSWSeFjWwM8yj6uNgAZ-2hMzY_vEokxnrcETWGTZtcNCmgmMwH4VLswDOtRWhjfVboo360PSTXxYjhiffD5B7CkkH0=@proton.me> (raw)
In-Reply-To: <20230614194255.1fb8f6c0.gary@garyguo.net>
> > /// Gets the value behind `this`.
> > @@ -266,7 +266,7 @@ pub fn get(&self) -> *mut T {
> > /// This function is useful to get access to the value without creating intermediate
> > /// references.
> > pub const fn raw_get(this: *const Self) -> *mut T {
> > - UnsafeCell::raw_get(this.cast::<UnsafeCell<T>>())
> > + UnsafeCell::raw_get(this.cast::<UnsafeCell<MaybeUninit<T>>>()).cast::<T>()
>
>
> This can just be `this.cast_mut().cast()` since all types involved are
> transparent.
I would advise against that, see [1]. It would be bad for people to
assume that one is always allowed to do that. I also like it explicit here.
[1]: https://github.com/rust-lang/unsafe-code-guidelines/issues/281
--
Cheers,
Benno
next prev parent reply other threads:[~2023-06-14 19:05 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-14 11:53 [PATCH] rust: make `UnsafeCell` the outer type in `Opaque` Alice Ryhl
2023-06-14 14:27 ` Benno Lossin
2023-06-14 14:37 ` Alice Ryhl
2023-06-14 15:30 ` Martin Rodriguez Reboredo
2023-06-14 18:42 ` Gary Guo
2023-06-14 19:04 ` Benno Lossin [this message]
2023-08-09 23:21 ` Miguel Ojeda
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