Work around rust-lang/rust#65863

Cargo.toml

@@ -11,4 +11,5 @@ debug=true
 [patch.crates-io]
 # https://github.com/tower-rs/tokio-tower/pull/6
 # optional -- just a perf optimization
+# comment this out if you want cargo doc to work!
 tokio-tower = { git = "https://github.com/tower-rs/tokio-tower.git", branch = "no-box" }

noria/src/controller.rs

@@ -58,7 +58,10 @@ where
     type Response = hyper::body::Bytes;
     type Error = failure::Error;
 
+    #[cfg(not(doc))]
     type Future = impl Future<Output = Result<Self::Response, Self::Error>> + Send;
+    #[cfg(doc)]
+    type Future = crate::doc_mock::Future<Result<Self::Response, Self::Error>>;
 
     fn poll_ready(&mut self, _: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
         Poll::Ready(Ok(()))
@@ -172,7 +175,10 @@ impl ControllerHandle<consensus::ZookeeperAuthority> {
 
 // this alias is needed to work around -> impl Trait capturing _all_ lifetimes by default
 // the A parameter is needed so it gets captured into the impl Trait
+#[cfg(not(doc))]
 type RpcFuture<A, R> = impl Future<Output = Result<R, failure::Error>>;
+#[cfg(doc)]
+type RpcFuture<A, R> = crate::doc_mock::FutureWithExtra<Result<R, failure::Error>, A>;
 
 // Needed b/c of https://github.com/rust-lang/rust/issues/65442
 async fn finalize<R, E>(

noria/src/doc_mock.rs

@@ -0,0 +1,50 @@
+//! This module exists entirely to work around https://github.com/rust-lang/rust/issues/65863
+
+/// impl Discover.
+///
+/// https://github.com/rust-lang/rust/issues/65863
+pub struct Discover<S>(std::marker::PhantomData<S>);
+
+impl<S> tower_discover::Discover for Discover<S> {
+    type Key = usize;
+    type Service = S;
+    type Error = tokio::io::Error;
+
+    fn poll_discover(
+        self: std::pin::Pin<&mut Self>,
+        _: &mut std::task::Context<'_>,
+    ) -> std::task::Poll<Result<tower_discover::Change<Self::Key, Self::Service>, Self::Error>>
+    {
+        loop {}
+    }
+}
+
+/// impl Future.
+///
+/// https://github.com/rust-lang/rust/issues/65863
+pub struct Future<O>(std::marker::PhantomData<O>);
+
+impl<O> std::future::Future for Future<O> {
+    type Output = O;
+    fn poll(
+        self: std::pin::Pin<&mut Self>,
+        _: &mut std::task::Context<'_>,
+    ) -> std::task::Poll<Self::Output> {
+        loop {}
+    }
+}
+
+/// impl Future.
+///
+/// https://github.com/rust-lang/rust/issues/65863
+pub struct FutureWithExtra<O, T>(std::marker::PhantomData<O>, std::marker::PhantomData<T>);
+
+impl<O, T> std::future::Future for FutureWithExtra<O, T> {
+    type Output = O;
+    fn poll(
+        self: std::pin::Pin<&mut Self>,
+        _: &mut std::task::Context<'_>,
+    ) -> std::task::Poll<Self::Output> {
+        loop {}
+    }
+}

noria/src/lib.rs

@@ -215,6 +215,8 @@ pub mod channel;
 #[allow(unreachable_pub)] // https://github.com/rust-lang/rust/issues/57411
 pub mod consensus;
 #[doc(hidden)]
+pub mod doc_mock;
+#[doc(hidden)]
 #[allow(unreachable_pub)] // https://github.com/rust-lang/rust/issues/57411
 pub mod internal;
 

noria/src/table.rs

@@ -213,7 +213,11 @@ type InnerService = multiplex::Client<
 impl Service<()> for Endpoint {
     type Response = InnerService;
     type Error = tokio::io::Error;
+
+    #[cfg(not(doc))]
     type Future = impl Future<Output = Result<Self::Response, Self::Error>>;
+    #[cfg(doc)]
+    type Future = crate::doc_mock::Future<Result<Self::Response, Self::Error>>;
 
     fn poll_ready(&mut self, _: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
         Poll::Ready(Ok(()))
@@ -256,16 +260,19 @@ fn make_table_discover(addr: SocketAddr) -> Discover {
 }
 
 // Unpin + Send bounds are needed due to https://github.com/rust-lang/rust/issues/55997
+#[cfg(not(doc))]
 type Discover = impl tower_discover::Discover<Key = usize, Service = InnerService, Error = tokio::io::Error>
     + Unpin
     + Send;
+#[cfg(doc)]
+type Discover = crate::doc_mock::Discover<InnerService>;
 
 pub(crate) type TableRpc = Buffer<
     ConcurrencyLimit<Balance<Discover, Tagged<LocalOrNot<Input>>>>,
     Tagged<LocalOrNot<Input>>,
 >;
 
-/// A failed [`SyncTable`] operation.
+/// A failed [`Table`] operation.
 #[derive(Debug, Fail)]
 pub enum TableError {
     /// The wrong number of columns was given when inserting a row.
@@ -577,7 +584,11 @@ impl Table {
 impl Service<Vec<TableOperation>> for Table {
     type Error = TableError;
     type Response = <TableRpc as Service<Tagged<LocalOrNot<Input>>>>::Response;
+
+    #[cfg(not(doc))]
     type Future = impl Future<Output = Result<Tagged<()>, TableError>> + Send;
+    #[cfg(doc)]
+    type Future = crate::doc_mock::Future<Result<Tagged<()>, TableError>>;
 
     fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
         for s in &mut self.shards {

noria/src/view.rs

@@ -40,7 +40,11 @@ type InnerService = multiplex::Client<
 impl Service<()> for Endpoint {
     type Response = InnerService;
     type Error = tokio::io::Error;
+
+    #[cfg(not(doc))]
     type Future = impl Future<Output = Result<Self::Response, Self::Error>>;
+    #[cfg(doc)]
+    type Future = crate::doc_mock::Future<Result<Self::Response, Self::Error>>;
 
     fn poll_ready(&mut self, _: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
         Poll::Ready(Ok(()))
@@ -81,14 +85,17 @@ fn make_views_discover(addr: SocketAddr) -> Discover {
 }
 
 // Unpin + Send bounds are needed due to https://github.com/rust-lang/rust/issues/55997
+#[cfg(not(doc))]
 type Discover = impl tower_discover::Discover<Key = usize, Service = InnerService, Error = tokio::io::Error>
     + Unpin
     + Send;
+#[cfg(doc)]
+type Discover = crate::doc_mock::Discover<InnerService>;
 
 pub(crate) type ViewRpc =
     Buffer<ConcurrencyLimit<Balance<Discover, Tagged<ReadQuery>>>, Tagged<ReadQuery>>;
 
-/// A failed [`SyncView`] operation.
+/// A failed [`View`] operation.
 #[derive(Debug, Fail)]
 pub enum ViewError {
     /// The given view is not yet available.
@@ -233,7 +240,11 @@ use self::results::{Results, Row};
 impl Service<(Vec<Vec<DataType>>, bool)> for View {
     type Response = Vec<Results>;
     type Error = ViewError;
+
+    #[cfg(not(doc))]
     type Future = impl Future<Output = Result<Self::Response, Self::Error>> + Send;
+    #[cfg(doc)]
+    type Future = crate::doc_mock::Future<Result<Self::Response, Self::Error>>;
 
     fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
         for s in &mut self.shards {