Update Tokio to use `std::future`. (#1120)

A first pass at updating Tokio to use `std::future`.

Implementations of `Future` from the futures crate are updated to implement
`Future` from std. Implementations of `Stream` are moved to a feature flag.

This commits disables a number of crates that have not yet been updated.

1 files changed, 3 insertions, 10 deletions

diff --git a/tokio/src/prelude.rs b/tokio/src/prelude.rs
index e364e8bf..000a680c 100644
--- a/tokio/src/prelude.rs
+++ b/tokio/src/prelude.rs
@@ -10,15 +10,8 @@
 //!
 //! The prelude may grow over time as additional items see ubiquitous use.
 
-pub use crate::util::{FutureExt, StreamExt};
-pub use futures::{future, stream, task, Async, AsyncSink, Future, IntoFuture, Poll, Sink, Stream};
-pub use std::io::{Read, Write};
-#[cfg(feature = "async-await-preview")]
-#[doc(inline)]
-pub use tokio_futures::{
-    io::{AsyncReadExt, AsyncWriteExt},
-    sink::SinkExt,
-    stream::StreamExt as StreamAsyncExt,
-};
+pub use std::future::Future;
+pub use std::task::{self, Poll};
+//pub use crate::util::{FutureExt, StreamExt};
 #[cfg(feature = "io")]
 pub use tokio_io::{AsyncRead, AsyncWrite};