If you're talking about editions, this isn't how they work at all; every edition continues to be supported forever. (The part about automated migration tooling is true, and nice.)

There've been a few cases where code was unsound and should never have compiled, but did due to compiler bugs, and then they fixed the bugs and the code stopped compiling. These were handled through deprecation warnings with timelines at least several months long (Rust releases a new version every six weeks), but usually didn't have automated migration tooling, and didn't fracture the language mostly because they were rare edge cases that most programmers didn't encounter.

Editions are still allowed to remove old syntax or even remove APIs - they only can’t break ABIs. So the code is still there once removed from an edition in previous editions, but such symbols don’t even get linked if they’re unused supporting progressive removal. And similarly, I could see editions getting completely removed in the future at some point. Eg rather than indefinitely maintaining editions, in 20 years have a checkpoint version of a compiler that supports the previous 20 years of editions and going forward editions older than 10 aren’t in the build (for example, assuming a meaningful maintenance burden, which is hard to predict when that happens and what a specific policy looks like).

Editions never remove APIs.

C++ almost never removes features because of the ABI compatibility guarantees. Programs compiled with older versions of the standard can be linked against newer versions.

This is allegedly because in the 80s companies would write software, fire the programmers, and throw the source code away once it compiled.

Fixing syntax by definition does not affect the ABI. And Rust has shown that both ABI and API compatibility can be achieved in the presence of several "versions" (editions) of the language in the same build.

Rust has shown that it’s yet another language that kind of sort of addresses 3% of the issues c/c++ has, tops.

Probably because like 95% of C++'s issues are self-inflicted and don't need to be addressed if you use a different language in the first place, and 1% of them are fundamentally unsolvable by any language.

Do you actually know Rust or were you just talking out if hour ass? I’d like you to enumerate even thirty problems of C or C++ that Rust doesn’t fix, never mind hundreds (because Rust fixes a metric shit ton of C/C++ problems!)

I really don't like C++ but it's hard to come up with thirty-odd times as many other terrible problems as the ones Rust addresses.

lol. A functions module system that’s easy to use and adopted? A package manager? A well implemented hash table? Fast compile times? Effectively no segfaults? Effectively no memory leaks? Comparatively no race condition bugs? A benchmark and unit test framework baked into the language? Auto optimization of the layout of structs? No UB?

I don’t know what you’re counting as “3% of the issues” but if those are the 3%, they sound like massive productivity and safety wins that’s not existed in a language with a similar performance profile to C/C++.

Is Rust faster to compile than C++?

Different (though related) things make compiling Rust slow. In both cases the compiler can spend a lot of time working on types which you, as programmer, weren't really thinking about. Rust cares about types which could exist based on what you wrote but which you never made, whereas C++ doesn't care about that, but it does need to do a lot of "from scratch" work for parametrised types that Rust doesn't have to because C++ basically does a lot of textual substitution in template expansion rather than "really" having parametrised typing.

If you're comparing Clang the backend optimiser work is identical in both cases it's LLVM.

People who've never measured often believe Rust's borrowck needs a lot of compiler effort but actual measurements don't agree - it's not free but it's very cheap (in terms of proportion of compiler runtime).

Rust is a single vendor. It's not really the same situation.

Having multiple compiler vendors is a problem IMO not a feature. It fragments the ecosystem - the code compiles fine with this compiler but not this other one. The maintenance of portable Rust code is significantly easier.

I think the way forward is multiple backends (LLVM + GCC) to improve platform support, but a single unified frontend that works correctly on all platforms is a good thing.

There is a single standard committee though. There is really nothing stopping them from shipping tooling that can do the conversions for people. The number of vendors isn't really the problem here. The problem is that the committee shifts that responsibility onto the vendors of the compiler rather than owning it themselves.