ci: enable clippy lints (#1335)

tokio-codec/src/bytes_codec.rs

@@ -4,7 +4,7 @@ use bytes::{BufMut, Bytes, BytesMut};
 use std::io;
 
 /// A simple `Codec` implementation that just ships bytes around.
-#[derive(Copy, Clone, Debug, Eq, PartialEq, Ord, PartialOrd, Hash)]
+#[derive(Copy, Clone, Debug, Eq, PartialEq, Ord, PartialOrd, Hash, Default)]
 pub struct BytesCodec(());
 
 impl BytesCodec {
@@ -19,7 +19,7 @@ impl Decoder for BytesCodec {
     type Error = io::Error;
 
     fn decode(&mut self, buf: &mut BytesMut) -> Result<Option<BytesMut>, io::Error> {
-        if buf.len() > 0 {
+        if !buf.is_empty() {
             let len = buf.len();
             Ok(Some(buf.split_to(len)))
         } else {

tokio-codec/src/framed_read.rs

@@ -153,7 +153,7 @@ pub fn framed_read2_with_buffer<T>(inner: T, mut buf: BytesMut) -> FramedRead2<T
     FramedRead2 {
         inner,
         eof: false,
-        is_readable: buf.len() > 0,
+        is_readable: !buf.is_empty(),
         buffer: buf,
     }
 }

tokio-codec/src/lines_codec.rs

@@ -190,6 +190,12 @@ impl Encoder for LinesCodec {
     }
 }
 
+impl Default for LinesCodec {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 /// An error occured while encoding or decoding a line.
 #[derive(Debug)]
 pub enum LinesCodecError {