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From:   Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Date:   Wed, 22 Feb 2023 13:29:29 +0100
Message-ID: <CANiq72kyULg=rPzK3QDqCJny3zjrOKzrH=v2PCTY_pUae-ODgw@mail.gmail.com>
Subject: Re: [PATCH] rust: time: New module for timekeeping functions
To:     Asahi Lina <lina@asahilina.net>
Cc:     Boqun Feng <boqun.feng@gmail.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Miguel Ojeda <ojeda@kernel.org>,
        Alex Gaynor <alex.gaynor@gmail.com>,
        Wedson Almeida Filho <wedsonaf@gmail.com>,
        Gary Guo <gary@garyguo.net>,
        =?UTF-8?Q?Bj=C3=B6rn_Roy_Baron?= <bjorn3_gh@protonmail.com>,
        John Stultz <jstultz@google.com>,
        Stephen Boyd <sboyd@kernel.org>, linux-kernel@vger.kernel.org,
        rust-for-linux@vger.kernel.org, asahi@lists.linux.dev,
        Heghedus Razvan <heghedus.razvan@protonmail.com>
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On Wed, Feb 22, 2023 at 5:46 AM Asahi Lina <lina@asahilina.net> wrote:
>
> For the actual Instant type, I was thinking it makes sense to just
> internally represent it as a newtype of Duration as well. Then all the
> math becomes trivial based on Duration operations, and when we replace
> Duration with a new u64 type it'll all work out the same. Fundamentally
> that means Instant types are internally stored as the Duration between
> the epoch (e.g. system boot) subject to the way that clock ticks, which
> I think is a reasonable internal representation?

Yeah, I think that is the way to go -- that is also how C++ represents
time points as well (including libstdc++, libc++ and STL from a quick
look), as well as Abseil too.

Cheers,
Miguel