[josephg]

I think a lot of the complaints about rust's difficulty come from people trying to use async in rust. I don't think the problem there is that rust is "different". The problem is that async rust isn't ready yet.

Rust's ecosystem pushes users toward using async for IO, and async support in the language & compiler is wildly incomplete. And it has been for years - the last big async feature (the async keyword) landed 2.5 years ago [1]. But its barely usable as-is. Building software with async today feels like trying to build a house out of daggers. Traits? Nope. Closures? Nope. Regular types? Only if they're Pinned. Your types are pinned, right? Iterators over async objects? Nope that doesn't work. Library support? Without traits, libraries are limited in what they can provide. Async rust? Batteries are not included.

We need TAIT, GAT, async closures, async iterators / streams, and a bunch of other little quality of life improvements before I'd consider it "done". I don't know where async's momentum went, but its a bit disappointing how halfbaked async is given how nice the rest of the language is.

[1] https://areweasyncyet.rs/

[Chio]

I agree wholeheartedly on your points regarding async, which is a topic I've tried to avoid so far in all of my Rust projects because of all the reasons you've already raised above and you really don't need it for most use-cases.

[tomjakubowski]

I totally agree. I've been working with Rust since before 1.0, and I love the language, and I never want to work on async code in Rust. The mental model is too hard for the payoff. I've also found debugging async code to be more nightmarish.

Most Rust applications I've worked on which have used some kind of parallelism/concurrency would be fine with a thread pool of workers and good old sync channels.

[tayo42]

How are people writing high throughput web/network services without async? Is there a async library to use. Like what do you reach for if you wanted to write redis or nginx with rust?

[TFortunato]

I'm not a rust expert by any means, but redis and nginx are both written in C, which doesn't have async as a language feature. Is there a reason the techniques used there wouldn't translate to rust, regardless of the state of rusts native async support?

[steveklabnik]

You can, it's just not as nice. Writing code this way can also require unsafe. Async in Rust is primarily about achieving zero-cost async code in a safe way.

[tayo42]

yeah, rusts async/await is just making it nicer to use the same ideas. like is there a libuv or libevent in the rust world thats being used?

[steveklabnik]

https://crates.io/crates/mio is the de-facto standard package that's similar to libuv/libevent. The most popular async executor, Tokio, is built on top of this. They're maintained by the same organization.

[tayo42]

I thought this library had alot less features then the popular c event loop libraries?

[steveklabnik]

I haven't written anything against it directly in years at this point, so I can't speak to that, it's just the best example of a library at the same level of abstraction.