chore: Prepare for Rust edition bump to 2024 (without autofix) (#27791)

Successor to #27779 - in this PR I've applied changes manually, without
futzing with if let lifetimes at all.

Release Notes:

- N/A

crates/rpc/src/auth.rs

@@ -43,7 +43,7 @@ pub fn random_token() -> String {
     let mut rng = thread_rng();
     let mut token_bytes = [0; 48];
     for byte in token_bytes.iter_mut() {
-        *byte = rng.gen();
+        *byte = rng.r#gen();
     }
     BASE64_URL_SAFE.encode(token_bytes)
 }

crates/rpc/src/peer.rs

@@ -116,7 +116,7 @@ impl Peer {
         create_timer: F,
     ) -> (
         ConnectionId,
-        impl Future<Output = anyhow::Result<()>> + Send,
+        impl Future<Output = anyhow::Result<()>> + Send + use<F, Fut, Out>,
         BoxStream<'static, Box<dyn AnyTypedEnvelope>>,
     )
     where
@@ -377,7 +377,7 @@ impl Peer {
         executor: gpui::BackgroundExecutor,
     ) -> (
         ConnectionId,
-        impl Future<Output = anyhow::Result<()>> + Send,
+        impl Future<Output = anyhow::Result<()>> + Send + use<>,
         BoxStream<'static, Box<dyn AnyTypedEnvelope>>,
     ) {
         let executor = executor.clone();
@@ -403,7 +403,7 @@ impl Peer {
         &self,
         receiver_id: ConnectionId,
         request: T,
-    ) -> impl Future<Output = Result<T::Response>> {
+    ) -> impl Future<Output = Result<T::Response>> + use<T> {
         self.request_internal(None, receiver_id, request)
             .map_ok(|envelope| envelope.payload)
     }
@@ -412,7 +412,7 @@ impl Peer {
         &self,
         receiver_id: ConnectionId,
         request: T,
-    ) -> impl Future<Output = Result<TypedEnvelope<T::Response>>> {
+    ) -> impl Future<Output = Result<TypedEnvelope<T::Response>>> + use<T> {
         self.request_internal(None, receiver_id, request)
     }
 
@@ -431,7 +431,7 @@ impl Peer {
         original_sender_id: Option<ConnectionId>,
         receiver_id: ConnectionId,
         request: T,
-    ) -> impl Future<Output = Result<TypedEnvelope<T::Response>>> {
+    ) -> impl Future<Output = Result<TypedEnvelope<T::Response>>> + use<T> {
         let envelope = request.into_envelope(0, None, original_sender_id.map(Into::into));
         let response = self.request_dynamic(receiver_id, envelope, T::NAME);
         async move {
@@ -457,7 +457,7 @@ impl Peer {
         receiver_id: ConnectionId,
         mut envelope: proto::Envelope,
         type_name: &'static str,
-    ) -> impl Future<Output = Result<(proto::Envelope, Instant)>> {
+    ) -> impl Future<Output = Result<(proto::Envelope, Instant)>> + use<> {
         let (tx, rx) = oneshot::channel();
         let send = self.connection_state(receiver_id).and_then(|connection| {
             envelope.id = connection.next_message_id.fetch_add(1, SeqCst);

crates/rpc/src/proto_client.rs

@@ -185,7 +185,7 @@ impl AnyProtoClient {
     pub fn request<T: RequestMessage>(
         &self,
         request: T,
-    ) -> impl Future<Output = anyhow::Result<T::Response>> {
+    ) -> impl Future<Output = anyhow::Result<T::Response>> + use<T> {
         let envelope = request.into_envelope(0, None, None);
         let response = self.0.request(envelope, T::NAME);
         async move {