From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-lj1-f179.google.com (mail-lj1-f179.google.com [209.85.208.179]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 51F8C1E47C4; Fri, 8 Nov 2024 12:22:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.208.179 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731068579; cv=none; b=rnn4TGsK+f2XBSGI9iRi3tcliWDVUA5uelWfqDxd9nANdrXyfb7YaQNplPr2HuXZ1R7e7lmmCCh6HanlfipME4/XYnxwl3Yy1Z9GHtohg80PJ9/AjlcL0aqq7iNAA+I+nVuzjkr5WUAtALCIX90gbyxFMwLrdU6K6ydZnWaWp6w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731068579; c=relaxed/simple; bh=2b7dYs/mmpG9lxNkDG8ZJcmFoOXZ0jGWnduqvTW4bAI=; h=MIME-Version:References:In-Reply-To:From:Date:Message-ID:Subject: To:Cc:Content-Type; b=jDt4FlaK7W9X1BSf/NLciLdP2rfiDuEu6kcuHHQ9Uj/nahidiE6GFPqisrPZ9b9ff/sn49jSO3GGm0y/nGnBEtwJDBAG73ykoblGC3pF6GRRIIQJvhNDfeIsBDUtsscXJqzvnkmKbwPxUNSSMCRKM64RCOJWK5C69fjmWwWtPXQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=CzBlbeoT; arc=none smtp.client-ip=209.85.208.179 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="CzBlbeoT" Received: by mail-lj1-f179.google.com with SMTP id 38308e7fff4ca-2fb518014b9so18873791fa.3; Fri, 08 Nov 2024 04:22:57 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1731068575; x=1731673375; darn=vger.kernel.org; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=2b7dYs/mmpG9lxNkDG8ZJcmFoOXZ0jGWnduqvTW4bAI=; b=CzBlbeoT6zZqY7ca2hG7MQ2Ln0bdlNwIXI58PNyHH34BBGMm4xmvkC4FbZRfXMZiPr HSx0dOcIRKugtvK4mWafPAwZpoTkZXUFD7ODIxeustzrMCyhwAp+UxD0CBvfPpSJUzBF Z3hpOhnTiSJlso805WkhoR4xhliN/cokv/9fT5pqqCT0A6jNmZjcInHxFINbBaZLZjX6 RKyCrwye+OB9bAizn8LqPyjku1kVdzOesxSlu9mDFr90ubGSrUr7RB5sdlEycjxfebJM uqP1OrKf66xO20YkMVAlnrF6AiI9Bd43S49HwCtLEBmII36/EOF74BMMRz9VSzw4guCh EhWQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1731068575; x=1731673375; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=2b7dYs/mmpG9lxNkDG8ZJcmFoOXZ0jGWnduqvTW4bAI=; b=TTXsxEIqHIwNOqw3JMUunsWH2gx3AyuWKLOI6v3EfzQu4H7BaCSNy1aH0s75uc2m6s Lgd4LabLpsYp5Cx8G+uZ7W+a2TRU6XEZhXEkAfEHMXqH6dfrZnlEd8pbfQ6wy92BD8zI F+2B38AP939Wx44raMgdOvhrVbP9rJoKaHR4tJYVBUN2PCDJBi8fUFdBPFXUUSiRBRNT 1Opui5WBEWXj1qevMGymHC8/2ZCvMyzrhPGJ7xFFwvnn3zKzfiEwy32ILkndcf/RzTny sAkEPlld5KC3Iiu2X/1o5JA+hYp7rRmsg6oTq1ctlclm6T9d0FAhdOt0ZV9Rs4NxM961 JDvA== X-Forwarded-Encrypted: i=1; AJvYcCWYEIYEA439vFX2DF1tJwNq0/vSLf3wYKVAaBAUtLuETIN/hEsKW+gkyuJ6uXkrB+iMz6liViakJ6u0wk8KvlA=@vger.kernel.org, AJvYcCWgIONuxmTzvl775c+8i/xhBcWhhGtjwrcy1XTCeQeIv3egTp9dgP75waHfZJ7QD71+RkPcTVTQc6H2beQ=@vger.kernel.org X-Gm-Message-State: AOJu0Yx0eo5VvHChbsCvF8x2vYR0TqnWEoIoFYRLG0f0195edry3HyPQ Kfiku4TmxNatWLwPSfaN+YJ9ndDp/pQcc+4LTlHzcj+R7r9PAKzxu+UCkpYTjq5EiQ7SFneolr0 TKDTpxll6mOJwdOT6xc7f7qM9A/EPIA== X-Google-Smtp-Source: AGHT+IHFlkxl7RBeHD/BOcMkJ5+RF5KJw/QO+lXdYTzZvhY/jURdU+h0iQcjQKD9OG0T4N4btsac1NazYjQjoh56jCs= X-Received: by 2002:a2e:b88e:0:b0:2fb:8774:4412 with SMTP id 38308e7fff4ca-2ff201b7ec1mr11556621fa.24.1731068575157; Fri, 08 Nov 2024 04:22:55 -0800 (PST) Precedence: bulk X-Mailing-List: rust-for-linux@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <20241104-borrow-mut-v2-0-de650678648d@gmail.com> <20241104-borrow-mut-v2-2-de650678648d@gmail.com> In-Reply-To: From: Tamir Duberstein Date: Fri, 8 Nov 2024 07:22:19 -0500 Message-ID: Subject: Re: [PATCH v2 2/6] rust: types: avoid `as` casts To: Alice Ryhl Cc: Miguel Ojeda , Alex Gaynor , Boqun Feng , Gary Guo , =?UTF-8?Q?Bj=C3=B6rn_Roy_Baron?= , Benno Lossin , Andreas Hindborg , Trevor Gross , Danilo Krummrich , rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Fri, Nov 8, 2024 at 6:35=E2=80=AFAM Alice Ryhl wr= ote: > > On Mon, Nov 4, 2024 at 10:20=E2=80=AFPM Tamir Duberstein wrote: > > > > Replace `as` casts with `cast{,_const,_mut}` which are a bit safer. > > > > Signed-off-by: Tamir Duberstein > > The compiler auto-converts from *mut to *const, so only cast_mut() is > necessary. I think this will still compile if you get rid of all of > the cast_const() calls. I thought that wouldn't work because of type inference but it does - I guess the compiler derefs *mut T to *const T before the cast() to *const U. Will change in v3, thanks.