stream: implement Error and Display for BroadcastStreamRecvError

[hyche]

Reuse the tokio::sync::broadcast::error::RecvError instead.

Motivation

I want to use the broadcast stream wrapper in the situtaion where some codes requiring the custom Error implementing std::error:Error trair, such as wrap_stream() function in hyper crate.

Solution

We can add impl std::error::Error, and core::fmt::Display for BroadcastStreamRecvError, but since the custom error doesn't provide any additional info, so it's better removing it and reusing the existing error from broadcast channel.

[Darksonn]

but since the custom error doesn't provide any additional info

It does provide additional info, namely that the wrapper never returns the Closed error as an error. Introducing a new error here was intentional.

Adding an impl for the Error trait is fine with me.

[hyche]

It does provide additional info, namely that the wrapper never returns the Closed error as an error. Introducing a new error here was intentional.

Thanks, understand it now!

Adding an impl for the Error trait is fine with me.

I have reverted and added the impl

[Darksonn]

Thanks.