Remove docs-only features from extension_trait.

This is the `@doc` rules, the shim trait impls, and the imports.

Author: nnethercote

src/future/future/mod.rs

@@ -21,11 +21,6 @@ cfg_unstable_default! {
 }
 
 extension_trait! {
-    use core::pin::Pin;
-    use core::ops::{Deref, DerefMut};
-
-    use crate::task::{Context, Poll};
-
     #[doc = r#"
         A future represents an asynchronous computation.
 
@@ -393,40 +388,4 @@ extension_trait! {
             TimeoutFuture::new(self, dur)
         }
     }
-
-    impl<F: Future + Unpin + ?Sized> Future for Box<F> {
-        type Output = F::Output;
-
-        fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
-            unreachable!("this impl only appears in the rendered docs")
-        }
-    }
-
-    impl<F: Future + Unpin + ?Sized> Future for &mut F {
-        type Output = F::Output;
-
-        fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
-            unreachable!("this impl only appears in the rendered docs")
-        }
-    }
-
-    impl<P> Future for Pin<P>
-    where
-        P: DerefMut + Unpin,
-        <P as Deref>::Target: Future,
-    {
-        type Output = <<P as Deref>::Target as Future>::Output;
-
-        fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
-            unreachable!("this impl only appears in the rendered docs")
-        }
-    }
-
-    impl<F: Future> Future for std::panic::AssertUnwindSafe<F> {
-        type Output = F::Output;
-
-        fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
-            unreachable!("this impl only appears in the rendered docs")
-        }
-    }
 }

src/io/buf_read/mod.rs

@@ -16,8 +16,6 @@ use crate::io;
 use crate::task::{Context, Poll};
 
 extension_trait! {
-    use std::ops::{Deref, DerefMut};
-
     #[doc = r#"
         Allows reading from a buffered byte stream.
 
@@ -283,62 +281,6 @@ extension_trait! {
             }
         }
     }
-
-    impl<T: BufRead + Unpin + ?Sized> BufRead for Box<T> {
-        fn poll_fill_buf(
-            self: Pin<&mut Self>,
-            cx: &mut Context<'_>,
-        ) -> Poll<io::Result<&[u8]>> {
-            unreachable!("this impl only appears in the rendered docs")
-        }
-
-        fn consume(self: Pin<&mut Self>, amt: usize) {
-            unreachable!("this impl only appears in the rendered docs")
-        }
-    }
-
-    impl<T: BufRead + Unpin + ?Sized> BufRead for &mut T {
-        fn poll_fill_buf(
-            self: Pin<&mut Self>,
-            cx: &mut Context<'_>,
-        ) -> Poll<io::Result<&[u8]>> {
-            unreachable!("this impl only appears in the rendered docs")
-        }
-
-        fn consume(self: Pin<&mut Self>, amt: usize) {
-            unreachable!("this impl only appears in the rendered docs")
-        }
-    }
-
-    impl<P> BufRead for Pin<P>
-    where
-        P: DerefMut + Unpin,
-        <P as Deref>::Target: BufRead,
-    {
-        fn poll_fill_buf(
-            self: Pin<&mut Self>,
-            cx: &mut Context<'_>,
-        ) -> Poll<io::Result<&[u8]>> {
-            unreachable!("this impl only appears in the rendered docs")
-        }
-
-        fn consume(self: Pin<&mut Self>, amt: usize) {
-            unreachable!("this impl only appears in the rendered docs")
-        }
-    }
-
-    impl BufRead for &[u8] {
-        fn poll_fill_buf(
-            self: Pin<&mut Self>,
-            cx: &mut Context<'_>,
-        ) -> Poll<io::Result<&[u8]>> {
-            unreachable!()
-        }
-
-        fn consume(self: Pin<&mut Self>, amt: usize) {
-            unreachable!("this impl only appears in the rendered docs")
-        }
-    }
 }
 
 pub fn read_until_internal<R: BufReadExt + ?Sized>(

src/io/read/mod.rs

@@ -22,12 +22,6 @@ pub use chain::Chain;
 pub use take::Take;
 
 extension_trait! {
-    use std::pin::Pin;
-    use std::ops::{Deref, DerefMut};
-
-    use crate::io;
-    use crate::task::{Context, Poll};
-
     #[doc = r#"
         Allows reading from a byte stream.
 
@@ -422,50 +416,6 @@ extension_trait! {
         }
 
     }
-
-    impl<T: Read + Unpin + ?Sized> Read for Box<T> {
-        fn poll_read(
-            self: Pin<&mut Self>,
-            cx: &mut Context<'_>,
-            buf: &mut [u8],
-        ) -> Poll<io::Result<usize>> {
-            unreachable!("this impl only appears in the rendered docs")
-        }
-    }
-
-    impl<T: Read + Unpin + ?Sized> Read for &mut T {
-        fn poll_read(
-            self: Pin<&mut Self>,
-            cx: &mut Context<'_>,
-            buf: &mut [u8],
-        ) -> Poll<io::Result<usize>> {
-            unreachable!("this impl only appears in the rendered docs")
-        }
-    }
-
-    impl<P> Read for Pin<P>
-    where
-        P: DerefMut + Unpin,
-        <P as Deref>::Target: Read,
-    {
-        fn poll_read(
-            self: Pin<&mut Self>,
-            cx: &mut Context<'_>,
-            buf: &mut [u8],
-        ) -> Poll<io::Result<usize>> {
-            unreachable!("this impl only appears in the rendered docs")
-        }
-    }
-
-    impl Read for &[u8] {
-        fn poll_read(
-            self: Pin<&mut Self>,
-            cx: &mut Context<'_>,
-            buf: &mut [u8],
-        ) -> Poll<io::Result<usize>> {
-            unreachable!("this impl only appears in the rendered docs")
-        }
-    }
 }
 
 /// Initializes a buffer if necessary.

src/io/seek/mod.rs

@@ -5,12 +5,6 @@ use seek::SeekFuture;
 use crate::io::SeekFrom;
 
 extension_trait! {
-    use std::ops::{Deref, DerefMut};
-    use std::pin::Pin;
-
-    use crate::io;
-    use crate::task::{Context, Poll};
-
     #[doc = r#"
         Allows seeking through a byte stream.
 
@@ -83,38 +77,4 @@ extension_trait! {
             SeekFuture { seeker: self, pos }
         }
     }
-
-    impl<T: Seek + Unpin + ?Sized> Seek for Box<T> {
-        fn poll_seek(
-            self: Pin<&mut Self>,
-            cx: &mut Context<'_>,
-            pos: SeekFrom,
-        ) -> Poll<io::Result<u64>> {
-            unreachable!("this impl only appears in the rendered docs")
-        }
-    }
-
-    impl<T: Seek + Unpin + ?Sized> Seek for &mut T {
-        fn poll_seek(
-            self: Pin<&mut Self>,
-            cx: &mut Context<'_>,
-            pos: SeekFrom,
-        ) -> Poll<io::Result<u64>> {
-            unreachable!("this impl only appears in the rendered docs")
-        }
-    }
-
-    impl<P> Seek for Pin<P>
-    where
-        P: DerefMut + Unpin,
-        <P as Deref>::Target: Seek,
-    {
-        fn poll_seek(
-            self: Pin<&mut Self>,
-            cx: &mut Context<'_>,
-            pos: SeekFrom,
-        ) -> Poll<io::Result<u64>> {
-            unreachable!("this impl only appears in the rendered docs")
-        }
-    }
 }

src/io/write/mod.rs

@@ -13,11 +13,6 @@ use write_vectored::WriteVectoredFuture;
 use crate::io::{self, IoSlice};
 
 extension_trait! {
-    use std::pin::Pin;
-    use std::ops::{Deref, DerefMut};
-
-    use crate::task::{Context, Poll};
-
     #[doc = r#"
         Allows writing to a byte stream.
 
@@ -245,80 +240,4 @@ extension_trait! {
             WriteFmtFuture { writer: self, res: Some(res), buffer: None, amt: 0 }
         }
     }
-
-    impl<T: Write + Unpin + ?Sized> Write for Box<T> {
-        fn poll_write(
-            self: Pin<&mut Self>,
-            cx: &mut Context<'_>,
-            buf: &[u8],
-        ) -> Poll<io::Result<usize>> {
-            unreachable!("this impl only appears in the rendered docs")
-        }
-
-        fn poll_flush(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<()>> {
-            unreachable!("this impl only appears in the rendered docs")
-        }
-
-        fn poll_close(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<()>> {
-            unreachable!("this impl only appears in the rendered docs")
-        }
-    }
-
-    impl<T: Write + Unpin + ?Sized> Write for &mut T {
-        fn poll_write(
-            self: Pin<&mut Self>,
-            cx: &mut Context<'_>,
-            buf: &[u8],
-        ) -> Poll<io::Result<usize>> {
-            unreachable!("this impl only appears in the rendered docs")
-        }
-
-        fn poll_flush(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<()>> {
-            unreachable!("this impl only appears in the rendered docs")
-        }
-
-        fn poll_close(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<()>> {
-            unreachable!("this impl only appears in the rendered docs")
-        }
-    }
-
-    impl<P> Write for Pin<P>
-    where
-        P: DerefMut + Unpin,
-        <P as Deref>::Target: Write,
-    {
-        fn poll_write(
-            self: Pin<&mut Self>,
-            cx: &mut Context<'_>,
-            buf: &[u8],
-        ) -> Poll<io::Result<usize>> {
-            unreachable!("this impl only appears in the rendered docs")
-        }
-
-        fn poll_flush(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<()>> {
-            unreachable!("this impl only appears in the rendered docs")
-        }
-
-        fn poll_close(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<()>> {
-            unreachable!("this impl only appears in the rendered docs")
-        }
-    }
-
-    impl Write for Vec<u8> {
-        fn poll_write(
-            self: Pin<&mut Self>,
-            cx: &mut Context<'_>,
-            buf: &[u8],
-        ) -> Poll<io::Result<usize>> {
-            unreachable!("this impl only appears in the rendered docs")
-        }
-
-        fn poll_flush(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<()>> {
-            unreachable!("this impl only appears in the rendered docs")
-        }
-
-        fn poll_close(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<()>> {
-            unreachable!("this impl only appears in the rendered docs")
-        }
-    }
 }

src/stream/stream/mod.rs

@@ -144,10 +144,6 @@ cfg_unstable! {
 }
 
 extension_trait! {
-    use std::ops::{Deref, DerefMut};
-
-    use crate::task::{Context, Poll};
-
     #[doc = r#"
         An asynchronous stream of values.
 
@@ -2389,40 +2385,4 @@ extension_trait! {
             Product::product(self)
         }
     }
-
-    impl<S: Stream + Unpin + ?Sized> Stream for Box<S> {
-        type Item = S::Item;
-
-        fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
-            unreachable!("this impl only appears in the rendered docs")
-        }
-    }
-
-    impl<S: Stream + Unpin + ?Sized> Stream for &mut S {
-        type Item = S::Item;
-
-        fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
-            unreachable!("this impl only appears in the rendered docs")
-        }
-    }
-
-    impl<P> Stream for Pin<P>
-    where
-        P: DerefMut + Unpin,
-        <P as Deref>::Target: Stream,
-    {
-        type Item = <<P as Deref>::Target as Stream>::Item;
-
-        fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
-            unreachable!("this impl only appears in the rendered docs")
-        }
-    }
-
-    impl<S: Stream> Stream for std::panic::AssertUnwindSafe<S> {
-        type Item = S::Item;
-
-        fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
-            unreachable!("this impl only appears in the rendered docs")
-        }
-    }
 }