Remove unnecessary imports

futures-channel/src/mpsc/mod.rs

@@ -88,7 +88,6 @@ use std::pin::Pin;
 use std::sync::{Arc, Mutex};
 use std::sync::atomic::AtomicUsize;
 use std::sync::atomic::Ordering::SeqCst;
-use std::usize;
 
 use crate::mpsc::queue::Queue;
 
@@ -288,13 +287,13 @@ struct State {
 }
 
 // The `is_open` flag is stored in the left-most bit of `Inner::state`
-const OPEN_MASK: usize = usize::MAX - (usize::MAX >> 1);
+const OPEN_MASK: usize = usize::max_value() - (usize::max_value() >> 1);
 
 // When a new channel is created, it is created in the open state with no
 // pending messages.
 const INIT_STATE: usize = OPEN_MASK;
 
-// The maximum number of messages that a channel can track is `usize::MAX >> 1`
+// The maximum number of messages that a channel can track is `usize::max_value() >> 1`
 const MAX_CAPACITY: usize = !(OPEN_MASK);
 
 // The maximum requested buffer size must be less than the maximum capacity of

futures-channel/src/mpsc/queue.rs

@@ -42,7 +42,6 @@
 //       slightly modified
 
 pub(super) use self::PopResult::*;
-use std::prelude::v1::*;
 
 use std::thread;
 use std::cell::UnsafeCell;

futures-executor/src/enter.rs

@@ -1,4 +1,3 @@
-use std::prelude::v1::*;
 use std::cell::Cell;
 use std::fmt;
 

futures-executor/src/local_pool.rs

@@ -8,7 +8,6 @@ use futures_util::stream::StreamExt;
 use pin_utils::pin_mut;
 use std::cell::{RefCell};
 use std::ops::{Deref, DerefMut};
-use std::prelude::v1::*;
 use std::rc::{Rc, Weak};
 use std::sync::Arc;
 use std::thread::{self, Thread};

futures-executor/src/thread_pool.rs

@@ -4,9 +4,7 @@ use futures_core::future::{Future, FutureObj};
 use futures_core::task::{Context, Poll, Spawn, SpawnError};
 use futures_util::future::FutureExt;
 use futures_util::task::{ArcWake, waker_ref};
-use num_cpus;
 use std::io;
-use std::prelude::v1::*;
 use std::sync::{Arc, Mutex};
 use std::sync::atomic::{AtomicUsize, Ordering};
 use std::sync::mpsc;

futures-io/src/lib.rs

@@ -18,7 +18,6 @@
 #[cfg(feature = "std")]
 mod if_std {
     use futures_core::task::{Context, Poll};
-    use std::boxed::Box;
     use std::cmp;
     use std::io as StdIo;
     use std::ops::DerefMut;

futures-test/src/io/read/interleave_pending.rs

@@ -1,7 +1,6 @@
 use futures_io::{self as io, AsyncBufRead, AsyncRead};
 use pin_utils::{unsafe_pinned, unsafe_unpinned};
 use std::{
-    marker::Unpin,
     pin::Pin,
     task::{Context, Poll},
 };

futures-test/src/io/write/interleave_pending_write.rs

@@ -1,7 +1,6 @@
 use futures_io::{self as io, AsyncWrite};
 use pin_utils::{unsafe_pinned, unsafe_unpinned};
 use std::{
-    marker::Unpin,
     pin::Pin,
     task::{Context, Poll},
 };

futures-test/src/io/write/limited_write.rs

@@ -2,7 +2,6 @@ use futures_io::{self as io, AsyncWrite};
 use pin_utils::{unsafe_pinned, unsafe_unpinned};
 use std::{
     cmp,
-    marker::Unpin,
     pin::Pin,
     task::{Context, Poll},
 };

futures-test/src/stream/interleave_pending.rs

@@ -1,7 +1,6 @@
 use futures_core::stream::Stream;
 use pin_utils::{unsafe_pinned, unsafe_unpinned};
 use std::{
-    marker::Unpin,
     pin::Pin,
     task::{Context, Poll},
 };

futures-util/src/future/catch_unwind.rs

@@ -4,7 +4,6 @@ use pin_utils::unsafe_pinned;
 use std::any::Any;
 use std::pin::Pin;
 use std::panic::{catch_unwind, UnwindSafe, AssertUnwindSafe};
-use std::prelude::v1::*;
 
 /// Future for the [`catch_unwind`](super::FutureExt::catch_unwind) method.
 #[derive(Debug)]

futures-util/src/io/copy_into.rs

@@ -1,7 +1,6 @@
 use futures_core::future::Future;
 use futures_core::task::{Context, Poll};
 use futures_io::{AsyncRead, AsyncWrite};
-use std::boxed::Box;
 use std::io;
 use std::pin::Pin;
 

futures-util/src/lock/mutex.rs

@@ -1,7 +1,7 @@
 use futures_core::future::{FusedFuture, Future};
 use futures_core::task::{Context, Poll, Waker};
 use slab::Slab;
-use std::{fmt, mem, usize};
+use std::{fmt, mem};
 use std::cell::UnsafeCell;
 use std::ops::{Deref, DerefMut};
 use std::pin::Pin;
@@ -113,7 +113,7 @@ impl<T> Mutex<T> {
 }
 
 // Sentinel for when no slot in the `Slab` has been dedicated to this object.
-const WAIT_KEY_NONE: usize = usize::MAX;
+const WAIT_KEY_NONE: usize = usize::max_value();
 
 /// A future which resolves when the target mutex has been successfully acquired.
 pub struct MutexLockFuture<'a, T> {

futures-util/src/stream/catch_unwind.rs

@@ -4,7 +4,6 @@ use pin_utils::{unsafe_pinned, unsafe_unpinned};
 use std::any::Any;
 use std::pin::Pin;
 use std::panic::{catch_unwind, UnwindSafe, AssertUnwindSafe};
-use std::prelude::v1::*;
 
 /// Stream for the [`catch_unwind`](super::StreamExt::catch_unwind) method.
 #[derive(Debug)]

futures-util/src/stream/concat.rs

@@ -1,6 +1,5 @@
 use core::fmt::{Debug, Formatter, Result as FmtResult};
 use core::pin::Pin;
-use core::default::Default;
 use futures_core::future::Future;
 use futures_core::stream::Stream;
 use futures_core::task::{Context, Poll};

futures-util/src/stream/futures_ordered.rs

@@ -3,7 +3,7 @@ use futures_core::future::Future;
 use futures_core::stream::Stream;
 use futures_core::task::{Context, Poll};
 use pin_utils::unsafe_pinned;
-use core::cmp::{Eq, PartialEq, PartialOrd, Ord, Ordering};
+use core::cmp::Ordering;
 use core::fmt::{self, Debug};
 use core::iter::FromIterator;
 use core::pin::Pin;

futures-util/src/stream/futures_unordered/mod.rs

@@ -16,7 +16,6 @@ use core::pin::Pin;
 use core::ptr;
 use core::sync::atomic::Ordering::SeqCst;
 use core::sync::atomic::{AtomicPtr, AtomicBool};
-use core::usize;
 use alloc::sync::{Arc, Weak};
 
 mod abort;

futures-util/src/try_stream/try_concat.rs

@@ -1,4 +1,3 @@
-use core::default::Default;
 use core::pin::Pin;
 use futures_core::future::Future;
 use futures_core::stream::TryStream;

futures/tests/stream.rs

@@ -1,8 +1,5 @@
 #![feature(async_await)]
 
-extern crate futures;
-extern crate futures_util;
-
 use futures::executor::block_on;
 use futures::stream;
 use futures_util::StreamExt;