tokio: include async-traits feature (#1314)

The `tokio` facade crate will depend on the `async-traits` feature flag in
sub crates.

azure-pipelines.yml

@@ -34,7 +34,7 @@ jobs:
       tokio-reactor: []
       tokio-signal: []
       tokio-tcp:
-        - incoming
+        - async-traits
 #       - tokio-tls
       tokio-udp: []
       tokio-uds:

tokio-tcp/Cargo.toml

@@ -22,7 +22,7 @@ categories = ["asynchronous"]
 publish = false
 
 [features]
-incoming = []
+async-traits = []
 
 [dependencies]
 async-util = { git = "https://github.com/tokio-rs/async" }

tokio-tcp/src/lib.rs

@@ -23,7 +23,7 @@
 //! [incoming_method]: struct.TcpListener.html#method.incoming
 //! [`Incoming`]: struct.Incoming.html
 
-#[cfg(feature = "incoming")]
+#[cfg(feature = "async-traits")]
 mod incoming;
 mod listener;
 pub mod split;

tokio-tcp/src/listener.rs

@@ -1,4 +1,4 @@
-#[cfg(feature = "incoming")]
+#[cfg(feature = "async-traits")]
 use super::incoming::Incoming;
 use super::TcpStream;
 use futures_core::ready;
@@ -288,7 +288,7 @@ impl TcpListener {
     ///     });
     /// # Ok::<_, Box<dyn std::error::Error>>(())
     /// ```
-    #[cfg(feature = "incoming")]
+    #[cfg(feature = "async-traits")]
     pub fn incoming(self) -> Incoming {
         Incoming::new(self)
     }

tokio/Cargo.toml

@@ -76,7 +76,7 @@ tokio-macros = { version = "0.2.0", optional = true, path = "../tokio-macros" }
 tokio-reactor = { version = "0.2.0", optional = true, path = "../tokio-reactor" }
 tokio-sync = { version = "0.2.0", optional = true, path = "../tokio-sync", features = ["async-traits"] }
 tokio-threadpool = { version = "0.2.0", optional = true, path = "../tokio-threadpool" }
-tokio-tcp = { version = "0.2.0", optional = true, path = "../tokio-tcp" }
+tokio-tcp = { version = "0.2.0", optional = true, path = "../tokio-tcp", features = ["async-traits"] }
 tokio-udp = { version = "0.2.0", optional = true, path = "../tokio-udp" }
 tokio-timer = { version = "0.3.0", optional = true, path = "../tokio-timer" }
 tracing-core = { version = "0.1", optional = true }