Add a separate trait for converting errors into server responses.

src/network/generic.rs

@@ -4,7 +4,7 @@ use crate::network::datagram::GenericDatagramSocket;
 use crate::network::listener::GenericListener;
 use crate::network::stream::GenericStream;
 use async_trait::async_trait;
-use std::fmt::Display;
+use std::fmt::{Debug, Display};
 
 #[async_trait]
 pub trait Networklike {
@@ -12,7 +12,7 @@ pub trait Networklike {
     /// for using only one; if you have a use case for separating your errors,
     /// please shoot the author(s) and email to split this into multiple types, one
     /// for each trait function.
-    type Error: Display + Into<ServerResponseStatus> + Send;
+    type Error: Debug + Display + IntoErrorResponse + Send;
 
     /// Connect to the given address and port, over this kind of network. The
     /// underlying stream should behave somewhat like a TCP stream ... which
@@ -46,3 +46,16 @@ pub trait Networklike {
         port: u16,
     ) -> Result<GenericDatagramSocket<Self::Error>, Self::Error>;
 }
+
+/// This trait is a hack; sorry about that. The thing is, we want to be able to
+/// convert Errors from the `Networklike` trait into a `ServerResponseStatus`,
+/// but want to do so on references to the error object rather than the actual
+/// object. This is for the paired reason that (a) we want to be able to use
+/// the errors in multiple places -- for example, to return a value to the client
+/// and then also to whoever called the function -- and (b) some common errors
+/// (I'm looking at you, `io::Error`) aren't `Clone`. So ... hence this overly-
+/// specific trait.
+pub trait IntoErrorResponse {
+    #[allow(clippy::wrong_self_convention)]
+    fn into_response(&self) -> ServerResponseStatus;
+}