Fix remaining clippy warnings

src/frame/headers.rs

@@ -309,17 +309,20 @@ impl fmt::Debug for Headers {
 
 // ===== util =====
 
-pub fn parse_u64(src: &[u8]) -> Result<u64, ()> {
+#[derive(Debug)]
+pub struct ParseU64Error;
+
+pub fn parse_u64(src: &[u8]) -> Result<u64, ParseU64Error> {
     if src.len() > 19 {
         // At danger for overflow...
-        return Err(());
+        return Err(ParseU64Error);
     }
 
     let mut ret = 0;
 
     for &d in src {
         if !(b'0'..=b'9').contains(&d) {
-            return Err(());
+            return Err(ParseU64Error);
         }
 
         ret *= 10;
@@ -333,7 +336,7 @@ pub fn parse_u64(src: &[u8]) -> Result<u64, ()> {
 
 #[derive(Debug)]
 pub enum PushPromiseHeaderError {
-    InvalidContentLength(Result<u64, ()>),
+    InvalidContentLength(Result<u64, ParseU64Error>),
     NotSafeAndCacheable,
 }
 
@@ -364,9 +367,9 @@ impl PushPromise {
         // A promised request "that indicates the presence of a request body
         // MUST reset the promised stream with a stream error"
         if let Some(content_length) = req.headers().get(header::CONTENT_LENGTH) {
-            let parsed_length = parse_u64(content_length.as_bytes());
-            if parsed_length != Ok(0) {
-                return Err(InvalidContentLength(parsed_length));
+            match parse_u64(content_length.as_bytes()) {
+                Ok(0) => (),
+                parsed => return Err(InvalidContentLength(parsed)),
             }
         }
         // "The server MUST include a method in the :method pseudo-header field

src/proto/streams/mod.rs

@@ -7,6 +7,7 @@ mod send;
 mod state;
 mod store;
 mod stream;
+#[allow(clippy::module_inception)]
 mod streams;
 
 pub(crate) use self::prioritize::Prioritized;

src/proto/streams/recv.rs

@@ -178,7 +178,7 @@ impl Recv {
             if let Some(content_length) = frame.fields().get(header::CONTENT_LENGTH) {
                 let content_length = match frame::parse_u64(content_length.as_bytes()) {
                     Ok(v) => v,
-                    Err(()) => {
+                    Err(_) => {
                         proto_err!(stream: "could not parse content-length; stream={:?}", stream.id);
                         return Err(Error::library_reset(stream.id, Reason::PROTOCOL_ERROR).into());
                     }
@@ -263,6 +263,7 @@ impl Recv {
     }
 
     /// Called by the client to get pushed response
+    #[allow(clippy::type_complexity)]
     pub fn poll_pushed(
         &mut self,
         cx: &Context,

src/proto/streams/streams.rs

@@ -1267,6 +1267,7 @@ impl OpaqueStreamRef {
         me.actions.recv.poll_response(cx, &mut stream)
     }
     /// Called by a client to check for a pushed request.
+    #[allow(clippy::type_complexity)]
     pub fn poll_pushed(
         &mut self,
         cx: &Context,

src/server.rs

@@ -407,6 +407,7 @@ where
     }
 
     #[doc(hidden)]
+    #[allow(clippy::type_complexity)]
     pub fn poll_accept(
         &mut self,
         cx: &mut Context<'_>,