alt Hacker NewsRe: async in traits, the feature was delayed because it relied on the "Generic Associated Types" and "Impl Trait in Traits" features. If Rust delayed the whole `async` feature for working on those pretty type-theoretic features what would you have thought?
Well in practice the async_trait crate worked just fine. If Rust delayed the whole async feature I'd have thought they'd have better been able to handle the function coloring problem via something like OCaml's algebraic effects rather than following the trend of JS and C# back then, as OCaml's came along much later after more research into the model.