chore: use ready macro from futures-core (#1300)

tokio/Cargo.toml

@@ -62,6 +62,7 @@ uds = ["tokio-uds"]
 [dependencies]
 # Only non-optional dependency...
 #futures = "0.1.20"
+futures-core-preview = "0.3.0-alpha.17"
 
 # Everything else is optional...
 bytes = { version = "0.4", optional = true }

tokio/src/io/copy.rs

@@ -1,3 +1,4 @@
+use futures_core::ready;
 use std::future::Future;
 use std::io;
 use std::pin::Pin;

tokio/src/io/read_exact.rs

@@ -1,3 +1,4 @@
+use futures_core::ready;
 use std::future::Future;
 use std::io;
 use std::marker::Unpin;

tokio/src/io/read_to_end.rs

@@ -1,5 +1,6 @@
 use tokio_io::AsyncRead;
 
+use futures_core::ready;
 use std::future::Future;
 use std::io;
 use std::pin::Pin;

tokio/src/io/write_all.rs

@@ -1,5 +1,6 @@
 use tokio_io::AsyncWrite;
 
+use futures_core::ready;
 use std::future::Future;
 use std::io;
 use std::mem;

tokio/src/lib.rs

@@ -75,15 +75,6 @@ macro_rules! if_runtime {
     )*)
 }
 
-macro_rules! ready {
-    ($e:expr) => {
-        match $e {
-            ::std::task::Poll::Ready(t) => t,
-            ::std::task::Poll::Pending => return ::std::task::Poll::Pending,
-        }
-    };
-}
-
 #[cfg(feature = "timer")]
 pub mod clock;
 #[cfg(feature = "codec")]