creusot VS rfcs

However, it seems that C is not "notified" whether --cfg thing is set, only the main crate being built is. Regardless of this flag, the dummy macro is always chosen. Am I doing something wrong? It should work; the Creusot project is doing something similar.

I believe https://github.com/xldenis/creusot is more similar in that it also uses proofs to prove rust code correct.

Wow that sounds really cool! I'm not an expert but does that mean that one day you could implement dependend types or refinement types in Rust as a crate ? I currently only know of tools like: Flux Creusot Kani Prusti

Easy reasoning does not end on memory safety. For example, deductive verification of Rust code is possible exactly because there's no reference aliasing in safe Rust

> No support for using something like separation logic within Rust itself to verify that unsafe code upholds the invariants that the safe language expects.

I think this is something we might see in the future. There are a lot of formal methods people who are interested in rust. Creusot in particular is pretty close to doing this - at least for simpler invariants

https://github.com/xldenis/creusot

Seems similar in principle to cruesot except as another language instead of as a layer on-top of rust.

You often encounter this entire thread of rhetoric when someone wants to put a diversion into the central argument, yeah but it doesn't ____.

But Rust does do that, match exhaustiveness, forcing the handling of errors and the type system enables things like CreuSAT [1] using creusot [2]

[1] https://news.ycombinator.com/item?id=31780128

[2] https://github.com/xldenis/creusot

> Creusot works by translating Rust code to WhyML, the verification and specification language of Why3. Users can then leverage the full power of Why3 to (semi)-automatically discharge the verification conditions!

Units of Measure, https://github.com/iliekturtles/uom

The base properties of the language enable things that can never be done in C++.

> I’ve been working on a tool: https://github.com/xldenis/creusot to put this into practice

Note that there are other tools trying to deal with formal statements about Rust code. AIUI, Rust developers are working on forming a proper working group for pursuing these issues. We might get a RFC-standardized way of expressing formal/logical conditions about Rust code, which would be a meaningful first step towards supporting proof-carrying code within Rust.

This is exciting! I've met with people from AdaCore and Ferrous systems (individually) several times and they're all serious, competent and motivated.

I'm curious what kinds of software they want to (eventually) verify, my PhD thesis is developing a verification tool for Rust (https://github.com/xldenis/creusot) and I'm always on the look out for case studies to push me forward.

The road to formally verified Rust is still long but in my unbiased opinion looking quite bright, especially compared to other languages like C.

RFC: Add large language models to Rust

https://github.com/rust-lang/rfcs/pull/3603

Man, SO and family has really gone downhill. That top answer is absolutely terrible. In fact, if you care, you can literally look at the RFC discussion here to see the actual debate: https://github.com/rust-lang/rfcs/pull/582

Basically, `for x in y` is kind of redundant, already sorta-kinda supported by itertools, and there's also a ton of macros that sorta-kinda do it already. It would just be language bloat at this point.

Literally has nothing to do with memory management.

Congrats!

> Similarly, uv does not yet generate a platform-agnostic lockfile. This matches pip-tools, but differs from Poetry and PDM, making uv a better fit for projects built around the pip and pip-tools workflows.

Do you expect to make the higher level workflow independent of requirements.txt / support a platform-agnostic lockfile? Being attached to Rye makes me think "no".

Without being platform agnostic, to me this is dead-on-arrival and unable to meet the "Cargo for Python" aim.

> uv supports alternate resolution strategies. By default, uv follows the standard Python dependency resolution strategy of preferring the latest compatible version of each package. But by passing --resolution=lowest, library authors can test their packages against the lowest-compatible version of their dependencies. (This is similar to Go's Minimal version selection.)

> uv allows for resolutions against arbitrary target Python versions. While pip and pip-tools always resolve against the currently-installed Python version (generating, e.g., a Python 3.12-compatible resolution when running under Python 3.12), uv accepts a --python-version parameter, enabling you to generate, e.g., Python 3.7-compatible resolutions even when running under newer versions.

This is great to see though!

I can understand it being a flag on these lower level, directly invoked dependency resolution operations.

While you aren't onto the higher level operations yet, I think it'd be useful to see if there is any cross-ecosystem learning we can do for my MSRV RFC: https://github.com/rust-lang/rfcs/pull/3537

How are you handling pre-releases in you resolution? Unsure how much of that is specified in PEPs. Its something that Cargo is weak in today but we're slowly improving.

In the early days of Rust there was a debate about whether to support "green threads" and in doing that require runtime support. It was actually implemented and included for a time but it creates problems when trying to do library or embedded code. At the time Go for example chose to go that route, and it was both nice (goroutines are nice to write and well supported) and expensive (effectively requires GC etc). I don't remember the details but there is a Rust RFC from when they removed green threads:

https://github.com/rust-lang/rfcs/blob/0806be4f282144cfcd55b...

I did some more digging. By RFC 899, I believe Alex Crichton meant PR 899 in this repo:

https://github.com/rust-lang/rfcs/pull/899

Still, no real discussion of why unbuffered stderr.

Rust has had a stable SIMD vector API[1] for a long time. But, it's architecture specific. The portable API[2] isn't stable yet, but you probably can't use the portable API for some of the more exotic uses of SIMD anyway. Indeed, that's true in .NET's case too[3].

Rust does all this SIMD too. It just isn't in the standard library. But the regex crate does it. Indeed, this is where .NET got its SIMD approach for multiple substring search from in the first place[4]. ;-)

You're right that Rust's standard library is conservatively vectorized though[5]. The main thing blocking this isn't the lack of SIMD availability. It's more about how the standard library is internally structured, and the fact that things like substring search are not actually defined in `std` directly, but rather, in `core`. There are plans to fix this[6].

[1]: https://doc.rust-lang.org/std/arch/index.html

[2]: https://doc.rust-lang.org/std/simd/index.html

[3]: https://github.com/dotnet/runtime/blob/72fae0073b35a404f03c3...

[4]: https://github.com/dotnet/runtime/pull/88394#issuecomment-16...

[5]: https://github.com/BurntSushi/memchr#why-is-the-standard-lib...

[6]: https://github.com/rust-lang/rfcs/pull/3469