don't use main()

src/macros.rs

@@ -79,14 +79,16 @@ macro_rules! try_print {
 /// ```
 /// use std::fs::File;
 /// use mio::Token;
-/// use rude::result::RudeResult;
+/// use rude::queue::SendQueue;
 /// use rude::try_send_error;
 ///
-/// fn main() -> RudeResult<()> {
+/// fn check_file() -> SendQueue {
 ///     let token = Token(12);
 ///     let file = try_send_error!(token, File::open(file!()));
-///     Ok(())
+///     SendQueue::ok(token)
 /// }
+///
+/// # assert_eq!(check_file().0[0].1, SendQueue::ok(Token(12)).0[0].1);
 /// ```
 #[macro_export]
 macro_rules! try_send_error {