From 2553ea1a7ae3d11f0232a5818949146fa3f68a29 Mon Sep 17 00:00:00 2001
From: Sean McArthur <sean@seanmonstar.com>
Date: Wed, 11 Dec 2019 15:50:36 -0800
Subject: [PATCH] feat(client): expose `hyper::client::connect::Connect` trait
 alias

This is *just* a "trait alias". It is automatically implemented for all
`Service<Uri>`s that have the required bounds. It's purpose being public
is to ease setting trait bounds outside of hyper. Therefore, it doesn't
have any exposed associated types, to prevent otherwise relying on any
super-traits that hyper requires.
---
 src/client/connect/http.rs |  7 +++++--
 src/client/connect/mod.rs  | 36 ++++++++++++++++++++++++++++--------
 src/client/mod.rs          |  4 ----
 3 files changed, 33 insertions(+), 14 deletions(-)

diff --git a/src/client/connect/http.rs b/src/client/connect/http.rs
index 08a08767..e4bdd7ca 100644
--- a/src/client/connect/http.rs
+++ b/src/client/connect/http.rs
@@ -637,10 +637,13 @@ mod tests {
 
     use ::http::Uri;
 
-    use super::super::sealed::Connect;
+    use super::super::sealed::{Connect, ConnectSvc};
     use super::HttpConnector;
 
-    async fn connect<C>(connector: C, dst: Uri) -> Result<C::Transport, C::Error>
+    async fn connect<C>(
+        connector: C,
+        dst: Uri,
+    ) -> Result<<C::_Svc as ConnectSvc>::Connection, <C::_Svc as ConnectSvc>::Error>
     where
         C: Connect,
     {
diff --git a/src/client/connect/mod.rs b/src/client/connect/mod.rs
index 5cb051ab..01e2dcf9 100644
--- a/src/client/connect/mod.rs
+++ b/src/client/connect/mod.rs
@@ -83,6 +83,7 @@ pub mod dns;
 mod http;
 #[cfg(feature = "tcp")]
 pub use self::http::{HttpConnector, HttpInfo};
+pub use self::sealed::Connect;
 
 /// Describes a type returned by a connector.
 pub trait Connection {
@@ -258,26 +259,45 @@ pub(super) mod sealed {
     // The `Sized` bound is to prevent creating `dyn Connect`, since they cannot
     // fit the `Connect` bounds because of the blanket impl for `Service`.
     pub trait Connect: Sealed + Sized {
-        /// The connected IO Stream.
-        type Transport: AsyncRead + AsyncWrite + Connection;
-        /// An error occured when trying to connect.
-        type Error: Into<Box<dyn StdError + Send + Sync>>;
-        /// A Future that will resolve to the connected Transport.
-        type Future: Future<Output = Result<Self::Transport, Self::Error>>;
         #[doc(hidden)]
+        type _Svc: ConnectSvc;
+        #[doc(hidden)]
+        fn connect(self, internal_only: Internal, dst: Uri) -> <Self::_Svc as ConnectSvc>::Future;
+    }
+
+    pub trait ConnectSvc {
+        type Connection: AsyncRead + AsyncWrite + Connection + Unpin + Send + 'static;
+        type Error: Into<Box<dyn StdError + Send + Sync>>;
+        type Future: Future<Output = Result<Self::Connection, Self::Error>> + Unpin + Send + 'static;
+
         fn connect(self, internal_only: Internal, dst: Uri) -> Self::Future;
     }
 
     impl<S, T> Connect for S
     where
-        S: tower_service::Service<Uri, Response = T> + Send,
+        S: tower_service::Service<Uri, Response = T> + Send + 'static,
         S::Error: Into<Box<dyn StdError + Send + Sync>>,
         S::Future: Unpin + Send,
         T: AsyncRead + AsyncWrite + Connection + Unpin + Send + 'static,
     {
-        type Transport = T;
+        type _Svc = S;
+
+        fn connect(self, _: Internal, dst: Uri) -> crate::service::Oneshot<S, Uri> {
+            crate::service::oneshot(self, dst)
+        }
+    }
+
+    impl<S, T> ConnectSvc for S
+    where
+        S: tower_service::Service<Uri, Response = T> + Send + 'static,
+        S::Error: Into<Box<dyn StdError + Send + Sync>>,
+        S::Future: Unpin + Send,
+        T: AsyncRead + AsyncWrite + Connection + Unpin + Send + 'static,
+    {
+        type Connection = T;
         type Error = S::Error;
         type Future = crate::service::Oneshot<S, Uri>;
+
         fn connect(self, _: Internal, dst: Uri) -> Self::Future {
             crate::service::oneshot(self, dst)
         }
diff --git a/src/client/mod.rs b/src/client/mod.rs
index 851e17e6..5f652fb0 100644
--- a/src/client/mod.rs
+++ b/src/client/mod.rs
@@ -150,8 +150,6 @@ impl Client<(), Body> {
 impl<C, B> Client<C, B>
 where
     C: Connect + Clone + Send + Sync + 'static,
-    C::Transport: Unpin + Send + 'static,
-    C::Future: Unpin + Send + 'static,
     B: Payload + Send + 'static,
     B::Data: Send,
 {
@@ -548,8 +546,6 @@ where
 impl<C, B> tower_service::Service<Request<B>> for Client<C, B>
 where
     C: Connect + Clone + Send + Sync + 'static,
-    C::Transport: Unpin + Send + 'static,
-    C::Future: Unpin + Send + 'static,
     B: Payload + Send + 'static,
     B::Data: Send,
 {