Impossible to implement async `IntoWs`?

[bspeice]

My goal is to build an object-pool Codec implementation to avoid allocations for all the frames/messages that come through a websocket. However, despite server/mod.rs mentioning the IntoWs trait, it appears impossible to implement in a separate crate because Upgrade in upgrade/async.rs is a struct that I can't patch the implementation for. Thus, I'd be able to adapt the underlying stream (so having new exotic things beyond just what tokio provides), but the protocol details are hidden from other crates.

Am I understanding this correctly? And is that all the more reason for #180 or extracting WsUpgrade into a trait?

[vi]

Why do you need your own implementation of IntoWs?

There is a blanket implementation provided for all AsyncRead + AsyncWrite + 'static.

Non-allocating buffers look a non-small change in rust-websocket architecture and is probably not worth pursuing now, given next-gen rust-websocket may be on the way.

You can also experiment with patching rust-websocket code using replace section in Cargo.toml.

[bspeice]

Non-allocating buffers isn't the issue, the IntoWs implementation is because that controls the Upgrade object being returned which ultimately determines the MessageProtocol used. I want to swap out MessageProtocol but in order to use the rest of the infrastructure I have to provide IntoWs.

EDIT: I should also mention that replacement via Cargo doesn't make much sense as I'd only need to edit one or two files, forking makes more sense at that point.