Cannot select on DuplexStream

[polyfractal]

It appears impossible to select over a DuplexStream channel. Select's handle method only accepts Receivers, and there is no way to access the Receiver channel in a DuplexStream either.

I'd be happy to put in a PR, but I'm unsure the best course of action. One of these needs to be done:

• Add a getter to obtain the DuplexStream's Receiver
• Make the DuplexStream struct members public

And then there is a question how the user interacts with Select. Should there be:

• Add a new handle method which accepts DuplexStreams (handle_duplex?)
• Make the existing handle more generic and check type at runtime (seems like a bad idea)
• Don't change anything, make the user pass in the DuplexStream's Receiver by hand

[thehydroimpulse]

/cc me

[thestinger]

This will all end up being thrown out as part of redesigning I/O and concurrency in the standard libraries. There's no reason to only support selection on channels rather than selection on both data structures and directly on IO operations / signals / timers.

[steveklabnik]

DuplexStream is gone, partially for this reason, if I recall.