Update futures to 0.3 (#463)

* Update futures to 0.3

* Fix a search-and-replace error

* Fix imports in tests

* Fix an import

Cargo.toml

@@ -32,8 +32,8 @@ broadcaster = { version = "0.2.6", optional = true, default-features = false, fe
 crossbeam-channel = "0.3.9"
 crossbeam-deque = "0.7.1"
 crossbeam-utils = "0.6.6"
-futures-core-preview = "=0.3.0-alpha.19"
+futures-core = "0.3.0"
-futures-io-preview = "=0.3.0-alpha.19"
+futures-io = "0.3.0"
 futures-timer = "1.0.2"
 kv-log-macro = "1.0.4"
 log = { version = "0.4.8", features = ["kv_unstable"] }
@@ -51,11 +51,7 @@ femme = "1.2.0"
 rand = "0.7.2"
 # surf = "1.0.2"
 tempdir = "0.3.7"
-futures-preview = { version = "=0.3.0-alpha.19", features = ["async-await"] }
+futures = "0.3.0"
-
-# These are used by the book for examples
-futures-channel-preview = "=0.3.0-alpha.19"
-futures-util-preview = "=0.3.0-alpha.19"
 
 [[test]]
 name = "stream"

docs/src/tutorial/all_together.md

@@ -4,16 +4,15 @@ At this point, we only need to start the broker to get a fully-functioning (in t
 
 ```rust,edition2018
 # extern crate async_std;
-# extern crate futures_channel;
+# extern crate futures;
-# extern crate futures_util;
 use async_std::{
     io::{self, BufReader},
     net::{TcpListener, TcpStream, ToSocketAddrs},
     prelude::*,
     task,
 };
-use futures_channel::mpsc;
+use futures::channel::mpsc;
-use futures_util::SinkExt;
+use futures::SinkExt;
 use std::{
     collections::hash_map::{HashMap, Entry},
     sync::Arc,

docs/src/tutorial/clean_shutdown.md

@@ -22,16 +22,15 @@ Let's add waiting to the server:
 
 ```rust,edition2018
 # extern crate async_std;
-# extern crate futures_channel;
+# extern crate futures;
-# extern crate futures_util;
 # use async_std::{
 #     io::{self, BufReader},
 #     net::{TcpListener, TcpStream, ToSocketAddrs},
 #     prelude::*,
 #     task,
 # };
-# use futures_channel::mpsc;
+# use futures::channel::mpsc;
-# use futures_util::SinkExt;
+# use futures::SinkExt;
 # use std::{
 #     collections::hash_map::{HashMap, Entry},
 #     sync::Arc,
@@ -156,16 +155,15 @@ And to the broker:
 
 ```rust,edition2018
 # extern crate async_std;
-# extern crate futures_channel;
+# extern crate futures;
-# extern crate futures_util;
 # use async_std::{
 #     io::{self, BufReader},
 #     net::{TcpListener, TcpStream, ToSocketAddrs},
 #     prelude::*,
 #     task,
 # };
-# use futures_channel::mpsc;
+# use futures::channel::mpsc;
-# use futures_util::SinkExt;
+# use futures::SinkExt;
 # use std::{
 #     collections::hash_map::{HashMap, Entry},
 #     sync::Arc,

docs/src/tutorial/connecting_readers_and_writers.md

@@ -12,15 +12,14 @@ The order of events "Bob sends message to Alice" and "Alice joins" is determined
 
 ```rust,edition2018
 # extern crate async_std;
-# extern crate futures_channel;
+# extern crate futures;
-# extern crate futures_util;
 # use async_std::{
 #     net::TcpStream,
 #     prelude::*,
 #     task,
 # };
-# use futures_channel::mpsc;
+# use futures::channel::mpsc;
-# use futures_util::sink::SinkExt;
+# use futures::sink::SinkExt;
 # use std::sync::Arc;
 #
 # type Result<T> = std::result::Result<T, Box<dyn std::error::Error + Send + Sync>>;

docs/src/tutorial/handling_disconnection.md

@@ -19,11 +19,10 @@ First, let's add a shutdown channel to the `connection_loop`:
 
 ```rust,edition2018
 # extern crate async_std;
-# extern crate futures_channel;
+# extern crate futures;
-# extern crate futures_util;
 # use async_std::net::TcpStream;
-# use futures_channel::mpsc;
+# use futures::channel::mpsc;
-# use futures_util::SinkExt;
+# use futures::SinkExt;
 # use std::sync::Arc;
 #
 # type Result<T> = std::result::Result<T, Box<dyn std::error::Error + Send + Sync>>;
@@ -70,11 +69,10 @@ We use the `select` macro for this purpose:
 
 ```rust,edition2018
 # extern crate async_std;
-# extern crate futures_channel;
+# extern crate futures;
-# extern crate futures_util;
 # use async_std::{net::TcpStream, prelude::*};
-use futures_channel::mpsc;
+use futures::channel::mpsc;
-use futures_util::{select, FutureExt};
+use futures::{select, FutureExt};
 # use std::sync::Arc;
 
 # type Receiver<T> = mpsc::UnboundedReceiver<T>;
@@ -122,16 +120,15 @@ The final code looks like this:
 
 ```rust,edition2018
 # extern crate async_std;
-# extern crate futures_channel;
+# extern crate futures;
-# extern crate futures_util;
 use async_std::{
     io::BufReader,
     net::{TcpListener, TcpStream, ToSocketAddrs},
     prelude::*,
     task,
 };
-use futures_channel::mpsc;
+use futures::channel::mpsc;
-use futures_util::{select, FutureExt, SinkExt};
+use futures::{select, FutureExt, SinkExt};
 use std::{
     collections::hash_map::{Entry, HashMap},
     future::Future,

docs/src/tutorial/implementing_a_client.md

@@ -16,14 +16,14 @@ With async, we can just use the `select!` macro.
 
 ```rust,edition2018
 # extern crate async_std;
-# extern crate futures_util;
+# extern crate futures;
 use async_std::{
     io::{stdin, BufReader},
     net::{TcpStream, ToSocketAddrs},
     prelude::*,
     task,
 };
-use futures_util::{select, FutureExt};
+use futures::{select, FutureExt};
 
 type Result<T> = std::result::Result<T, Box<dyn std::error::Error + Send + Sync>>;
 

docs/src/tutorial/sending_messages.md

@@ -13,14 +13,13 @@ if Alice and Charley send two messages to Bob at the same time, Bob will see the
 
 ```rust,edition2018
 # extern crate async_std;
-# extern crate futures_channel;
+# extern crate futures;
-# extern crate futures_util;
 # use async_std::{
 #     net::TcpStream,
 #     prelude::*,
 # };
-use futures_channel::mpsc; // 1
+use futures::channel::mpsc; // 1
-use futures_util::sink::SinkExt;
+use futures::sink::SinkExt;
 use std::sync::Arc;
 
 # type Result<T> = std::result::Result<T, Box<dyn std::error::Error + Send + Sync>>;

src/path/path.rs

@@ -615,9 +615,9 @@ impl Path {
     /// ```no_run
     /// # fn main() -> std::io::Result<()> { async_std::task::block_on(async {
     /// #
-    /// use async_std::path::Path;
     /// use async_std::fs;
-    /// use futures_util::stream::StreamExt;
+    /// use async_std::path::Path;
+    /// use async_std::prelude::*;
     ///
     /// let path = Path::new("/laputa");
     /// let mut dir = fs::read_dir(&path).await.expect("read_dir call failed");

src/sync/barrier.rs

@@ -204,9 +204,9 @@ impl BarrierWaitResult {
 
 #[cfg(test)]
 mod test {
-    use futures_channel::mpsc::unbounded;
+    use futures::channel::mpsc::unbounded;
-    use futures_util::sink::SinkExt;
+    use futures::sink::SinkExt;
-    use futures_util::stream::StreamExt;
+    use futures::stream::StreamExt;
 
     use crate::sync::{Arc, Barrier};
     use crate::task;