X-Git-Url: https://code.octet-stream.net/m17rt/blobdiff_plain/2813fcb83452c7fd91d799a984613a616180a067..bd5155840661f90aab8c06413fb1e9f256824b55:/m17app/src/tnc.rs

diff --git a/m17app/src/tnc.rs b/m17app/src/tnc.rs
index 99bacc7..e7799b4 100644
--- a/m17app/src/tnc.rs
+++ b/m17app/src/tnc.rs
@@ -6,8 +6,20 @@ use std::io::{Read, Write};
 /// via a working implementation of try_clone(). We do not require `Clone` directly
 /// as this could not be fulfilled by `TcpStream`.
 pub trait Tnc: Read + Write + Sized + Send + 'static {
+    /// Return a copy of this TNC.
+    ///
+    /// `M17App` will use this to create a second instance of the supplied TNC then use
+    /// one of them for reading and one of them for writing, concurrently across two threads.
+    ///
+    /// Implementations do not need to worry about trying to make two simultaneous reads or
+    /// two simultaneous writes do something sensible. `M17App` will not do this and it would
+    /// probably produce garbled KISS messages anyway.
     fn try_clone(&mut self) -> Result<Self, TncError>;
+
+    /// Start I/O.
     fn start(&mut self) -> Result<(), TncError>;
+
+    /// Shut down I/O - it is assumed we cannot restart.
     fn close(&mut self) -> Result<(), TncError>;
 }
 
@@ -19,7 +31,7 @@ pub enum TncError {
 
 impl Tnc for std::net::TcpStream {
     fn try_clone(&mut self) -> Result<Self, TncError> {
-        self.try_clone().map_err(|_| TncError::Unknown)
+        std::net::TcpStream::try_clone(self).map_err(|_| TncError::Unknown)
     }
 
     fn start(&mut self) -> Result<(), TncError> {