rust-for-linux.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Benno Lossin <benno.lossin@proton.me>
To: Boqun Feng <boqun.feng@gmail.com>
Cc: rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org,
	"Thomas Gleixner" <tglx@linutronix.de>,
	"Alice Ryhl" <aliceryhl@google.com>,
	"Miguel Ojeda" <ojeda@kernel.org>,
	"Alex Gaynor" <alex.gaynor@gmail.com>,
	"Wedson Almeida Filho" <wedsonaf@gmail.com>,
	"Gary Guo" <gary@garyguo.net>,
	"Björn Roy Baron" <bjorn3_gh@protonmail.com>,
	"Andreas Hindborg" <a.hindborg@samsung.com>,
	"John Stultz" <jstultz@google.com>,
	"Stephen Boyd" <sboyd@kernel.org>,
	"Valentin Obst" <kernel@valentinobst.de>
Subject: Re: [PATCH 2/5] rust: time: Introduce Duration type
Date: Wed, 27 Mar 2024 11:18:28 +0000	[thread overview]
Message-ID: <e93d124b-e2db-4a7d-848c-6d4fb389d780@proton.me> (raw)
In-Reply-To: <ZgMDGYMj7V50PZbP@boqun-archlinux>

On 26.03.24 18:17, Boqun Feng wrote:
> On Tue, Mar 26, 2024 at 10:11:07AM -0700, Boqun Feng wrote:
> [...]
>>>> +impl Duration {
>>>> +    /// Creates a new duration of `ns` nanoseconds.
>>>> +    pub const fn new(ns: i64) -> Self {
>>>> +        Self { inner: ns }
>>>> +    }
>>>> +
>>>> +    /// Divides the number of nanoseconds by a compile-time constant.
>>>> +    #[inline]
>>>> +    fn divns_constant<const DIV: i64>(self) -> i64 {
>>>> +        self.to_ns() / DIV
>>>> +    }
>>>
>>> I am a bit confused, why is this better than writing
>>> `self.to_ns() / DIV` at the callsite?
>>>
>>
>> Hmm.. you're right, there should be no difference I think. If there is
>> nothing I'm missing from Alice, I will drop this function in the next
>> version.
>>
> 
> On a second thought, I think this prevents accidentally divide a
> non-const value, in other words, if you use this function, you're
> guaranteed the divisor is a constant, and you have the compiler checking
> that for you. So in that sense, I think it makes sense to remain it
> here. Thoughts?

I don't see the value in that. It does not prevent me from just doing
`self.to_ns() / DIV` now. I imagine that 99% of the time users will want
to get milliseconds or microseconds and we should have methods for that
(when we have users). But for the last 1% I don't think we need this
method.

-- 
Cheers,
Benno


  reply	other threads:[~2024-03-27 11:18 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-03-24 22:33 [PATCH 0/5] rust: time: Add clock read support Boqun Feng
2024-03-24 22:33 ` [PATCH 1/5] rust: time: doc: Add missing C header link to jiffies Boqun Feng
2024-03-26 16:44   ` Benno Lossin
2024-03-24 22:33 ` [PATCH 2/5] rust: time: Introduce Duration type Boqun Feng
2024-03-26 16:50   ` Benno Lossin
2024-03-26 17:11     ` Boqun Feng
2024-03-26 17:17       ` Boqun Feng
2024-03-27 11:18         ` Benno Lossin [this message]
2024-03-24 22:33 ` [PATCH 3/5] rust: time: Introduce clock reading framework Boqun Feng
2024-03-26 17:00   ` Benno Lossin
2024-03-26 19:19     ` Boqun Feng
2024-03-27 12:50       ` Benno Lossin
2024-03-27 17:49         ` Boqun Feng
2024-03-24 22:33 ` [PATCH 4/5] rust: time: Support reading CLOCK_MONOTONIC Boqun Feng
2024-03-26 17:03   ` Benno Lossin
2024-03-26 19:21     ` Boqun Feng
2024-03-24 22:33 ` [PATCH 5/5] rust: time: Add Instant::elapsed() for monotonic clocks Boqun Feng
2024-03-26 17:13   ` Benno Lossin
2024-03-26 18:00     ` Boqun Feng
2024-03-26 18:04       ` Boqun Feng
2024-03-27  1:09       ` Boqun Feng
2024-03-27 11:31         ` Benno Lossin

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=e93d124b-e2db-4a7d-848c-6d4fb389d780@proton.me \
    --to=benno.lossin@proton.me \
    --cc=a.hindborg@samsung.com \
    --cc=alex.gaynor@gmail.com \
    --cc=aliceryhl@google.com \
    --cc=bjorn3_gh@protonmail.com \
    --cc=boqun.feng@gmail.com \
    --cc=gary@garyguo.net \
    --cc=jstultz@google.com \
    --cc=kernel@valentinobst.de \
    --cc=linux-kernel@vger.kernel.org \
    --cc=ojeda@kernel.org \
    --cc=rust-for-linux@vger.kernel.org \
    --cc=sboyd@kernel.org \
    --cc=tglx@linutronix.de \
    --cc=wedsonaf@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).