Converted Connection into an enumeration for extensibility.

src/conn.rs

@@ -1,17 +1,22 @@
 use std::io::{BufferedWriter, IoResult, TcpStream};
 use data::Message;
 
-pub struct Connection(pub TcpStream);
+pub enum Connection {
+    TcpConn(TcpStream),
+}
 
 pub fn connect(host: &str, port: u16) -> IoResult<Connection> {
     let socket = try!(TcpStream::connect(host, port));
-    Ok(Connection(socket))
+    Ok(TcpConn(socket))
 }
 
 fn send_internal(conn: &Connection, msg: &str) -> IoResult<()> {
-    let &Connection(ref tcp) = conn;
-    let mut writer = BufferedWriter::new(tcp.clone());
-    writer.write_str(msg)
+    match conn {
+        &TcpConn(ref tcp) => {
+            let mut writer = BufferedWriter::new(tcp.clone());
+            writer.write_str(msg)
+        }
+    }
 }
 
 pub fn send(conn: &Connection, msg: Message) -> IoResult<()> {