[tmandry]

Futures were developed outside Rust core, in a third-party library, before being brought into the language. Working with them in combinator form definitely was less ergonomic, but async/await fixes that.

[steveklabnik]

Fun fact: there was a future type in the rust standard library, long, long ago.

https://doc.rust-lang.org/0.10/sync/struct.Future.html

[brson]

That version of Rust also did async I/O in the runtime. Async I/O has always been part of Rust. The model changed because there was too much overhead doing it the more ergonomic way and it got booted out of the runtime.

[steveklabnik]

Yep, this is a great point.

Someday, we should get a book about the history of Rust together...

[tmandry]

I didn’t know about this.. I’d love to read that book :)