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[73.105.0.253]) by smtp.gmail.com with ESMTPSA id 00721157ae682-78691d8f62dsm1071397b3.10.2025.11.03.06.26.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 03 Nov 2025 06:26:05 -0800 (PST) Date: Mon, 3 Nov 2025 09:26:03 -0500 From: Yury Norov To: Miguel Ojeda Cc: Alexandre Courbot , Alice Ryhl , Danilo Krummrich , Miguel Ojeda , Joel Fernandes , Jesung Yang , Boqun Feng , Gary Guo , =?iso-8859-1?Q?Bj=F6rn?= Roy Baron , Benno Lossin , Andreas Hindborg , Trevor Gross , linux-kernel@vger.kernel.org, rust-for-linux@vger.kernel.org Subject: Re: [PATCH 1/2] rust: add BitInt integer wrapping type Message-ID: References: <20251031-bounded_ints-v1-0-e2dbcd8fda71@nvidia.com> <20251031-bounded_ints-v1-1-e2dbcd8fda71@nvidia.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Mon, Nov 03, 2025 at 03:10:01PM +0100, Miguel Ojeda wrote: > On Mon, Nov 3, 2025 at 3:17 AM Yury Norov wrote: > > > > Rust _must_ do the same thing to at least be arithmetically > > compatible to the big brother. > > No, Rust doesn't need to do anything of the sort, sorry. > > The point here is not to copy what C does, but to improve on it. > > In particular, we definitely do not want to have anything like integer > promotions and arithmetic conversions from C. This is exactly what the patch does: +/// let v = BitInt::::from_expr(15); +/// +/// // Common operations are supported against the backing type. +/// assert_eq!(v + 5, 20); +/// assert_eq!(v / 3, 5);