rfcs VS polonius

That nobody has gone through the effort of collating its requirements and writing an RFC after https://github.com/rust-lang/rfcs/pull/770 was closed (back in 2015).

I assume a big issue is that this is full of edge cases up the ass, and the value is somewhat limited in the sense that if you know you want durable writes you'll sync() and know you're fucked if you get an error, but close() does not guarantee a sync to disk, as the linux man page indicates:

> A successful close does not guarantee that the data has been successfully saved to disk, as the kernel uses the buffer cache to defer writes.

I never heard of "German strings" in place of the small string optimization before! And there had been way too many proposals to add such types to the standard library [1] [2] [3] [4]. My understanding is that:

1. Both `Vec` and `String` should share the same layout as part of the standard library's contract.

2. Unlike `String`, the equivalent optimization for `Vec` is more questionable especially when T might be any type. C++ standard libraries frequently do implement multiple layouts for std::string but not for std::vector for the same reason.

3. Rust never allows an implicit copying of `String` in the first place, which greatly benefits from the SSO, so the lack of SSO in Rust is less important compared to C++.

[1] https://github.com/rust-lang/rust/issues/4991

[2] https://github.com/rust-lang/rust/issues/20198

[3] https://github.com/rust-lang/rfcs/pull/2990

[4] https://github.com/rust-lang/unsafe-code-guidelines/issues/4...

nrc was poking at the problem in 2016 https://internals.rust-lang.org/t/struct-field-defaults/3412 which led to this RFC https://github.com/rust-lang/rfcs/pull/1806

It got postponed because it wasn't going to make it into Rust 2018: https://github.com/rust-lang/rfcs/pull/1806#issuecomment-327...

You can check out Rust-langs RFC Repo to see their well-documented and thorough process for an RFC.

Finally, I found the answer in the RFC Book (RFC stands for Request For Comments). RFC 2451 from 2018-05-30 that starts with the following lines:

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.

Alas, poor Yorick; I knew him well, Ferris.

(Slightly more seriously, the project to replace the borrow checker was called Polonius[1], so it wouldn't be the first Hamlet reference in Rust land.)

[1] https://github.com/rust-lang/polonius

Correctness prover which uses lifetimes (Polonius).

And, well, polonius (Rust borrow checker magic) I believe is built on datalog-ish concepts: https://github.com/rust-lang/polonius

There is also polonius (https://github.com/rust-lang/polonius) which should replace the borrow checker but does not receive a lot of development resources.

This is eventually going to be a feature-complete compiler, targeting a specific rustc version. I believe the plan is to use polonius [1], presumably as an "optional" feature so they can build a stage 1 without it, use that to build polonius, then build the final compiler with it included.

[1] https://github.com/rust-lang/polonius

E.g. there you may just stop using current borrow-checker and switch to Polonius.

The borrow checker is too dumb (https://github.com/rust-lang/polonius) fixes a lot of this.

It looks like an official borrow checker implementation called Polonius uses it as a dependency, so it makes sense: https://github.com/rust-lang/polonius/blob/981785c101b68ff54...

If you click around a little, you end up on a blog post with this tidbit:

> This project got put together rather suddenly, in response to some work the Rust folks are doing[1] on their new and improved borrow checker.

I don't think I could tell you more than "Frank wrote it to help rust folks who were previously doing work with differential-dataflow directly."

1. https://github.com/rust-lang/polonius/pull/36#issuecomment-3...

Good news is that there's also works going on to relax the restrictions, like polonius. But it seems that it still have a long way to go before it can land in stable Rust...