Why websocket depends on future crate?

[doowonee]

Hello maybe It is about rust asnyc echo system but I have a question.

Tokio does not support Sink(future crate) trait from here tokio-rs/tokio#4909. But Stream(future crate) can created by tokio-stream crate.

When I split websocket and it gives me Sink and Stream. But tokio does not support forward() function. So I have to import future crate

I wonder why axum uses Sink and Stream which depends on future crate. Is it impossible to remove dependency future crate and only use tokio crate?

[davidpdrsn]

That's impossible to remove. That's just what async rust is today.

[doowonee]

So future crate is essential in rust async echo system even more than tokio which provide async runtime. I understand Thank you!

[davidpdrsn]

Tokio provides the runtime. Futures provides many utilities and abstractions.