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Date:   Tue, 6 Dec 2022 17:22:46 +0000
From:   Wei Liu <wei.liu@kernel.org>
To:     ojeda@kernel.org
Cc:     Wedson Almeida Filho <wedsonaf@gmail.com>,
        Alex Gaynor <alex.gaynor@gmail.com>,
        Boqun Feng <boqun.feng@gmail.com>, Gary Guo <gary@garyguo.net>,
        =?iso-8859-1?Q?Bj=F6rn?= Roy Baron <bjorn3_gh@protonmail.com>,
        rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org,
        patches@lists.linux.dev, Josh Triplett <josh@joshtriplett.org>,
        Wei Liu <wei.liu@kernel.org>
Subject: Re: [PATCH v1] rust: alloc: remove the `borrow` module (`ToOwned`,
 `Cow`)
Message-ID: <Y496ZhJF2ND+ND3L@liuwe-devbox-debian-v2>
References: <20221206010519.39075-1-ojeda@kernel.org>
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On Tue, Dec 06, 2022 at 02:05:19AM +0100, ojeda@kernel.org wrote:
> From: Miguel Ojeda <ojeda@kernel.org>
> 
> The `Cow` type [1] requires that its generic parameter type implements
> the `ToOwned` trait [2], which provides a method to create owned data
> from borrowed data, usually by cloning.
> 
> However, it is infallible, and thus in most cases it is not useful for
> the kernel. [3]
> 
> Therefore, introduce `cfg(no_borrow)` to remove the `borrow` module
> (which contains `ToOwned` and `Cow`) from `alloc`.
> 
> Link: https://doc.rust-lang.org/alloc/borrow/enum.Cow.html [1]
> Link: https://doc.rust-lang.org/alloc/borrow/trait.ToOwned.html [2]
> Link: https://lore.kernel.org/rust-for-linux/20221204103153.117675b1@GaryWorkstation/ [3]
> Cc: Gary Guo <gary@garyguo.net>
> Cc: Wedson Almeida Filho <wedsonaf@gmail.com>
> Cc: Josh Triplett <josh@joshtriplett.org>
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Reviewed-by: Wei Liu <wei.liu@kernel.org>