tokio-0.2.0-alpha4 AsyncRead and AsyncWrite traits are not the same as futures-0.3.0-alpha18 versions.

[farnz]

tokio-0.2's AsyncWrite, AsyncRead etc are out of sync with the futures-0.3 versions - e.g. tokio's AsyncWrite is implemented for Vec<u8>, while futures' AsyncWrite is implemented for Cursor<T> where T: AsMut<[u8]>.

Rather than supplying its own versions of these traits, could tokio reuse the futures versions?

[Nemo157]

See also #1297

[carllerche]

Currently, the primary difference between the two traits is Tokio's reliance on Buf and BufMut. Adding these to futures-io has been proposed here, but not accepted.

There are probably other issues that I would like to see addressed w/ the current traits (both futures-io and tokio), but on a personal note, I am punting on that until I am able to update Tokio to the latest mio & bytes crates.

[theduke]

So with futures 0.3 out, what is the path forward here?

The _buf methods were not adopted, yet it would be really quite unfortunate if tokio continued to use different traits.

[jebrosen]

An idea that I think others have mentioned, but not posted here, would be for tokio to implement futures_io::AsyncRead for each type that also implements tokio::io::AsyncRead, under an optional dependency. This probably can't be done with a blanket impl, but a macro could be doable.

See also tokio-rs/tokio-compat#2 (adding I/O to tokio-compat)

[theduke]

Linking #1744 for reference.

[tamird]

#1744 is now closed; @carllerche where should people be following along on efforts (if any) to converge Async{Read,Write} with those of futures?