Fix Clippy 1.90 lints

Two things were caught by new version of Clippy:
- Unnecessary parentheses.
- Unused struct, that should have been caught before. It wasn't, most
likely because of Clippy bug.
- One instance of manual impl of is_multiple_of.

Author: Lorak-mmk

scylla-cql/src/serialize/row_tests.rs

@@ -225,6 +225,7 @@ fn test_map_errors() {
 // etc. that usually pop up when generating code for empty structs.
 #[derive(SerializeRow)]
 #[scylla(crate = crate)]
+#[allow(dead_code)] // TODO: Change to expect after bumping MSRV to 1.90
 struct TestRowWithNoColumns {}
 
 #[derive(SerializeRow, Debug, PartialEq, Eq, Default)]

scylla-macros/src/deserialize/row.rs

@@ -631,7 +631,7 @@ impl DeserializeUnorderedGenerator<'_> {
         let field_idents = fields.iter().map(|f| f.ident.as_ref().unwrap());
         let nonskipped_field_names = fields
             .iter()
-            .filter(|&f| (!f.skip))
+            .filter(|&f| !f.skip)
             .map(|f| f.cql_name_literal());
 
         let field_finalizers = fields.iter().map(|f| self.generate_finalize_field(f));

scylla-proxy/src/proxy.rs

@@ -1061,7 +1061,7 @@ impl ProxyWorker {
 
     async fn receiver_from_driver(
         self,
-        mut read_half: (impl AsyncRead + Unpin),
+        mut read_half: impl AsyncRead + Unpin,
         request_processor_tx: mpsc::UnboundedSender<RequestFrame>,
         compression: CompressionReader,
     ) {
@@ -1096,7 +1096,7 @@ impl ProxyWorker {
 
     async fn receiver_from_cluster(
         self,
-        mut read_half: (impl AsyncRead + Unpin),
+        mut read_half: impl AsyncRead + Unpin,
         response_processor_tx: mpsc::UnboundedSender<ResponseFrame>,
         compression: CompressionReader,
     ) {
@@ -1133,7 +1133,7 @@ impl ProxyWorker {
 
     async fn sender_to_driver(
         self,
-        mut write_half: (impl AsyncWrite + Unpin),
+        mut write_half: impl AsyncWrite + Unpin,
         mut responses_rx: mpsc::UnboundedReceiver<ResponseFrame>,
         mut connection_close_notifier: ConnectionCloseNotifier,
         mut terminate_notifier: TerminateNotifier,
@@ -1180,7 +1180,7 @@ impl ProxyWorker {
 
     async fn sender_to_cluster(
         self,
-        mut write_half: (impl AsyncWrite + Unpin),
+        mut write_half: impl AsyncWrite + Unpin,
         mut requests_rx: mpsc::UnboundedReceiver<RequestFrame>,
         mut connection_close_notifier: ConnectionCloseNotifier,
         mut terminate_notifier: TerminateNotifier,

scylla/src/network/connection.rs

@@ -1317,7 +1317,7 @@ impl Connection {
     ) -> Result<RemoteHandle<()>, std::io::Error> {
         async fn spawn_router_and_get_handle(
             config: HostConnectionConfig,
-            stream: (impl AsyncRead + AsyncWrite + Send + 'static),
+            stream: impl AsyncRead + AsyncWrite + Send + 'static,
             receiver: mpsc::Receiver<Task>,
             error_sender: tokio::sync::oneshot::Sender<ConnectionError>,
             orphan_notification_receiver: mpsc::UnboundedReceiver<RequestId>,
@@ -1402,7 +1402,7 @@ impl Connection {
 
     async fn router(
         config: HostConnectionConfig,
-        stream: (impl AsyncRead + AsyncWrite),
+        stream: impl AsyncRead + AsyncWrite,
         receiver: mpsc::Receiver<Task>,
         error_sender: tokio::sync::oneshot::Sender<ConnectionError>,
         orphan_notification_receiver: mpsc::UnboundedReceiver<RequestId>,
@@ -1468,7 +1468,7 @@ impl Connection {
     }
 
     async fn reader(
-        mut read_half: (impl AsyncRead + Unpin),
+        mut read_half: impl AsyncRead + Unpin,
         handler_map: &StdMutex<ResponseHandlerMap>,
         event_sender: Option<mpsc::Sender<Event>>,
         compression: Option<Compression>,
@@ -1553,7 +1553,7 @@ impl Connection {
     }
 
     async fn writer(
-        mut write_half: (impl AsyncWrite + Unpin),
+        mut write_half: impl AsyncWrite + Unpin,
         handler_map: &StdMutex<ResponseHandlerMap>,
         mut task_receiver: mpsc::Receiver<Task>,
         write_coalescing_delay: Option<WriteCoalescingDelay>,

scylla/tests/integration/macros/hygiene.rs

@@ -302,10 +302,7 @@ macro_rules! test_crate {
             _scylla::DeserializeRow, _scylla::SerializeRow, PartialEq, Debug,
         )]
         #[scylla(crate = _scylla)]
-        // We would like to have this `expect(dead_code)`, but it does not work for
-        // SerializeRow with by-name flavor. See https://github.com/scylladb/scylla-rust-driver/issues/1429
-        // After fixing the above issue, we can add allow(dead_code)
-        // After also bumping MSRV to 1.89+ we can add expect(dead_code).
+        #[allow(dead_code)] // TODO: Change to expect after bumping MSRV to 1.90
         struct TestRowByName {
             #[scylla(skip)]
             a: ::core::primitive::i32,