Possible to implement `IoSafe` for `PipeReader` / `PipeWriter` ?

[jk-ozlabs]

I'm looking to do async reads from a std::io::PipeReader:

let (reader, writer) = std::io::pipe()?;
let mut async_reader = smol::Async::new(reader)?;

However, std::io::PipeReader is not one of the IoSafe impls, so we don't have AsyncRead (and therefore AsyncReadExt) available.

It would be possible to add the impls in async-io:

 unsafe impl IoSafe for std::io::StderrLock<'_> {}
 unsafe impl IoSafe for std::io::StdinLock<'_> {}
 unsafe impl IoSafe for std::io::StdoutLock<'_> {}
+unsafe impl IoSafe for std::io::PipeReader {}
+unsafe impl IoSafe for std::io::PipeWriter {}
 unsafe impl IoSafe for std::net::TcpStream {}
 unsafe impl IoSafe for std::process::ChildStdin {}
 unsafe impl IoSafe for std::process::ChildStdout {}

However, this requires rust >= 1.87, for the introduction of PipeReader/PipeWriter, and I assume we're working with a MSRV of 1.63 at present.

Is there a conventional way to gate these on a cfg macro / build setting / something else?

Thanks!

[notgull]

In the past, we've gated based on build.rs gates cfg macros. I think we can do this here as well.

[jk-ozlabs]

ok, thanks for the info! PR is up, at #237.