Pre-1.0. Rust removed the green-threads runtime prior to stabilization.
replyI personally think this was one of the most important changes Rust made; without it, Rust would have been interesting but would not have been able to compete directly with C and C++ for systems programming.
> without it, Rust would have been interesting
replyThanks for articulating what I’ve failed to do for a decade.
Yep, it would've just been another OCaml with C style syntax.
replyOr another Go, with a mandatory runtime, which would have been a useful language but not something you'd add to a production OS kernel or firmware or similar.
replyI wonder if we'd have eventually saw something like Nim, which has optional green thread concurrency and a garbage collector. Rust does not have these currently right? At least I haven't heard of them.
replySome of Rust's async runtimes seem pretty similar to "optional green threads". There's no garbage collection; you can get something like a reference-counted GC by using Arc everywhere, but it's neither automatic nor universal.
replyWould we have gotten to "optional"? Maybe! But it's hard to predict the counterfactual, especially when substantial success usually has components of both design and luck/right-place-right-time. Rust hit a sweet spot, and it's not clear how a different history of Rust would have turned out.