Re: what's missing from newer C? [was: [PATCH v5 0/9] Introduce Rust ....]

From: Pierre-Emmanuel Patry <pierre-emmanuel.patry@embecosm.com>
Date: Oct 6, 2025, 09:13 UTC
Message-ID: <9eea6006-1dfb-4822-adfc-3af1222b1e01@embecosm.com>
In-Reply-To: <20251004010201.M85772@dcvr>

> As I understand it, the borrow checker is a big part of the slow
> compile times

 From what can been observed in benchmarks (perf.rust-lang.org) the 
borrow checker is not the biggest part of the slow compile times. It 
certainly isn't the quickest one but I wouldn't make it the culprit.

> As someone who's worked on implementing async/green threads for
> a VM

You seems to be mixing async and green threads within the same point. Green threads were removed almost ten years ago before rust 1.0. You may learn more about that removal from RFC 230.

>  It's never been a big problem to me
> with RCU and proper understanding of POSIX semantics.

But it has been a problem with less experienced people and that kind of problem easily slip through a review.

> it seems to be mainly dealing with colons vs underscores

It doesn't. This is only true when dealing from a C perspective where everything can be seen from everywhere. Huge identifiers are harder to read. Namespaces offer context dependent short identifiers that won't leak in the whole TU.

> AFAIK, Rust modules + crates are centrally controlled and
> publishing requires an account on a proprietary service owned
> and operated by a convicted monopolist.

Publishing on that platform indeed requires an account on GitHub. It's probably worth mentioning they're willing to change it but do not have the resources nor the bandwidth to do so.

crates.io is not a mandatory step, it's the default and easiest way to publish or retrieve a dependencies just like cargo is with building. More services like this one may appear but it looks very expensive to run and maintain.

Pierre-Emmanuel