Crust of Rust: async/await

Jon Gjengset · 246K views · 2021 · 2:34:01

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C, C++, Rust, Go & systems languagestutorial

Why Hacker News recommends it

Recommended as a deep, practical dive for learning how Rust async works.

What it is

Jon Gjengset's long live-coding Crust of Rust episode on async/await, focused on the mental model for using it rather than on Futures, Pin and Wakers internals. Topics include awaiting multiple futures, cancellation, executors and select.

Recommended by 2 HN commenters across 2 different months, 2023 to 2026.

What Hacker News said

Recommends SnowProblem · 2023-08 · on “Learning Async Rust with Too Many Web Servers”

Impressive! Especially the part on async where they built up the Future trait and runtime from first principles. If it interests you, these two videos are also great deep dives into Rust async [1] [2]. Rust's model is a little different from other languages in a powerful way. [1] [LINK] [2] [this video]

Recommends lame_lexem · 2026-05 · on “Async Rust never left the MVP state”

there is a chapter on async in comprehensive rust and rustbook which ought to bring you up to speed there is the async book but it is largely unfinished you can watch John Gjengset's crust of rust async, decrusting tokio, and why what, and how of pinning in rust then there are tokio-lessons and tokio tutorial which teach how to use tokio runtime and there are also good blogposts by phil-oop and rose wright on how async works [LINK] [LINK] [LINK] [this video] [LINK] [LINK] [LINK] [LINK] [LINK] [LINK]

Cites sph · 2023-06 · on “The Rust I wanted had no future”

Very interesting insight from Graydon, in hindsight I too would have loved something more towards ML than C++. I never liked the kitchen sink approach that I see first C++, now Rust moving towards, but I respect what Rust has managed to solidify into. It's a good language. That said, I still hate async with a passion, it makes the language more complex and not very elegant (i.e. function coloring). And now that I know how it works behind the scene (thanks to Jon Gjengset [1]), it feels so complicated and hacky, a mediocre very high level concept that someone managed to implement as a zero-cost abstraction. Impressive, but still a bad idea. I'm sure the pro of having a BDFL instead of a commi