stable_deref_trait VS zig

To elaborate, there is a recurring trend of sound C programs turning into unsound Rust programs, because shared mutability is often necessary but Stacked Borrows places strict conditions on constructing &mut T (they invalidate some but not all aliasing *const T), and it's less ergonomic to work solely in raw pointers and avoid creating Box or long-lasting &mut T (or for intrusive collections, any &mut T at all).

For example, matklad (the author of rust-analyzer, one of the preeminent Rust programmers and someone I'd expect to get code right) made a recent blog post on "Caches In Rust" (https://matklad.github.io/2022/06/11/caches-in-rust.html). The cache is built around https://docs.rs/elsa, which is built around https://docs.rs/stable_deref_trait/latest/stable_deref_trait..., which is unsound for Box and violates stacked borrows in its current form (https://github.com/Storyyeller/stable_deref_trait/issues/15). However, the rules may be relaxed or more ergonomic alternatives added (https://github.com/rust-lang/unsafe-code-guidelines/issues/3...), it's uncertain right now.

(Also I go by "they".)

Unsafe Rust is an esoteric language without iron-clad guarantees, and type-level programming and async Rust is an esoteric metalanguage (https://hirrolot.github.io/posts/rust-is-hard-or-the-misery-...). For example, matklad made a recent blog post on "Caches In Rust" (https://matklad.github.io/2022/06/11/caches-in-rust.html). The cache is built around https://docs.rs/elsa, which is built around https://docs.rs/stable_deref_trait/latest/stable_deref_trait..., which is unsound for Box and violates stacked borrows: https://github.com/Storyyeller/stable_deref_trait/issues/15

There is a recurring trend of sound C programs turning into unsound Rust programs, because shared mutability is often necessary but it's difficult to avoid creating &mut, and Stacked Borrows places strict conditions on constructing &mut T (they invalidate some but not all aliasing *const T).

The cache is built around https://docs.rs/elsa, which is built around https://docs.rs/stable_deref_trait/latest/stable_deref_trait/trait.StableDeref.html, which is unsound for Box and violates stacked borrows: https://github.com/Storyyeller/stable_deref_trait/issues/15

StableDeref has multiple issues under the current Stacked Borrows model: https://github.com/Storyyeller/stable_deref_trait/issues/15

It's "Zig" not "Zag". https://ziglang.org/ Zig is under heavy development, but there's a single page https://ziglang.org/documentation/0.12.0/ that is a reasonably comprehensive source of truth about the current state of the language.

There is an issue proposing this approach: https://github.com/ziglang/zig/issues/4284

https://github.com/ziglang/zig/issues/224

e.g.:

> > When debugging/prototyping, it's useful to comment out a line without having to refactor, e.g.

When writing code in a scripting language, sometimes you need that extra bit of performance (or maybe an async feature from Zig).

NodeJS is by no means a slow runtime, it wouldn’t be so popular if it was. But compared to Bun, it’s slow. Bun was built from the ground up with speed in mind, using both JavascriptCore and Zig. The Bun team spent an enormous amount of time and energy trying to make Bun fast, including lots of profiling, benchmarking, and optimizations.

ntdll.dll!RtlUserThreadStart()

There are valid reasons to use APIs from NTDLL. Where I disagree with zig#1840 is the idea that it is always better to use NTDLL versions of API. Every other software ecosystem uses the standard Win32 APIs and diverging from that without a good reason seems like a good way to have unexpected behavior. One concrete example is most users and programmers expect Windows to redirect some file system paths when running on WOW64. But this is implemented in Kernel32, not ntdll.

https://github.com/ziglang/zig/issues/11894