Remove extension_trait.

At this point, `extension_trait` is basically an expensive no-op. This
commit removes it. The next commit will adjust the indentation.

Author: nnethercote

src/future/future/mod.rs

@@ -22,7 +22,6 @@ cfg_unstable_default! {
 
 pub use core::future::Future as Future;
 
-extension_trait! {
     #[doc = r#"
         Extension methods for [`Future`].
 
@@ -45,7 +44,7 @@ extension_trait! {
         /// ```
         #[cfg(feature = "unstable")]
         #[cfg_attr(feature = "docs", doc(cfg(unstable)))]
-        fn delay(self, dur: Duration) -> [DelayFuture<Self>]
+        fn delay(self, dur: Duration) -> DelayFuture<Self>
         where
             Self: Sized,
         {
@@ -70,7 +69,7 @@ extension_trait! {
         #[cfg_attr(feature = "docs", doc(cfg(unstable)))]
         fn flatten(
             self,
-        ) -> [FlattenFuture<Self, <Self::Output as IntoFuture>::Future>]
+        ) -> FlattenFuture<Self, <Self::Output as IntoFuture>::Future>
         where
             Self: Sized,
             <Self as Future>::Output: IntoFuture,
@@ -112,7 +111,7 @@ extension_trait! {
         fn race<F>(
             self,
             other: F,
-        ) -> [Race<Self, F>]
+        ) -> Race<Self, F>
         where
             Self: std::future::Future + Sized,
             F: std::future::Future<Output = <Self as std::future::Future>::Output>,
@@ -158,7 +157,7 @@ extension_trait! {
         fn try_race<F, T, E>(
             self,
             other: F
-        ) -> [TryRace<Self, F>]
+        ) -> TryRace<Self, F>
         where
             Self: std::future::Future<Output = Result<T, E>> + Sized,
             F: std::future::Future<Output = <Self as std::future::Future>::Output>,
@@ -195,7 +194,7 @@ extension_trait! {
         fn join<F>(
             self,
             other: F
-        ) -> [Join<Self, F>]
+        ) -> Join<Self, F>
         where
             Self: std::future::Future + Sized,
             F: std::future::Future,
@@ -242,7 +241,7 @@ extension_trait! {
         fn try_join<F, A, B, E>(
             self,
             other: F
-        ) -> [TryJoin<Self, F>]
+        ) -> TryJoin<Self, F>
         where
             Self: std::future::Future<Output = Result<A, E>> + Sized,
             F: std::future::Future<Output = Result<B, E>>,
@@ -278,13 +277,12 @@ extension_trait! {
         "#]
         #[cfg(any(all(feature = "default", feature = "unstable"), feature = "docs"))]
         #[cfg_attr(feature = "docs", doc(cfg(unstable)))]
-        fn timeout(self, dur: Duration) -> [TimeoutFuture<Self>]
+        fn timeout(self, dur: Duration) -> TimeoutFuture<Self>
             where Self: Sized
         {
             TimeoutFuture::new(self, dur)
         }
     }
-}
 
 impl<T: Future + ?Sized> FutureExt for T {}
 

src/io/buf_read/mod.rs

@@ -17,7 +17,6 @@ use crate::task::{Context, Poll};
 
 pub use futures_io::AsyncBufRead as BufRead;
 
-extension_trait! {
     #[doc = r#"
         Extension methods for [`BufRead`].
 
@@ -78,7 +77,7 @@ extension_trait! {
             &'a mut self,
             byte: u8,
             buf: &'a mut Vec<u8>,
-        ) -> [ReadUntilFuture<'a, Self>]
+        ) -> ReadUntilFuture<'a, Self>
         where
             Self: Unpin,
         {
@@ -131,7 +130,7 @@ extension_trait! {
         fn read_line<'a>(
             &'a mut self,
             buf: &'a mut String,
-        ) -> [ReadLineFuture<'a, Self>]
+        ) -> ReadLineFuture<'a, Self>
         where
             Self: Unpin,
         {
@@ -237,7 +236,6 @@ extension_trait! {
             }
         }
     }
-}
 
 impl<T: BufRead + ?Sized> BufReadExt for T {}
 

src/io/read/mod.rs

@@ -23,7 +23,6 @@ pub use take::Take;
 
 pub use futures_io::AsyncRead as Read;
 
-extension_trait! {
     #[doc = r#"
         Extension methods for [`Read`].
 
@@ -64,7 +63,7 @@ extension_trait! {
         fn read<'a>(
             &'a mut self,
             buf: &'a mut [u8],
-        ) -> [ReadFuture<'a, Self>]
+        ) -> ReadFuture<'a, Self>
         where
             Self: Unpin
         {
@@ -86,7 +85,7 @@ extension_trait! {
         fn read_vectored<'a>(
             &'a mut self,
             bufs: &'a mut [IoSliceMut<'a>],
-        ) -> [ReadVectoredFuture<'a, Self>]
+        ) -> ReadVectoredFuture<'a, Self>
         where
             Self: Unpin,
         {
@@ -123,7 +122,7 @@ extension_trait! {
         fn read_to_end<'a>(
             &'a mut self,
             buf: &'a mut Vec<u8>,
-        ) -> [ReadToEndFuture<'a, Self>]
+        ) -> ReadToEndFuture<'a, Self>
         where
             Self: Unpin,
         {
@@ -162,7 +161,7 @@ extension_trait! {
         fn read_to_string<'a>(
             &'a mut self,
             buf: &'a mut String,
-        ) -> [ReadToStringFuture<'a, Self>]
+        ) -> ReadToStringFuture<'a, Self>
         where
             Self: Unpin,
         {
@@ -217,7 +216,7 @@ extension_trait! {
         fn read_exact<'a>(
             &'a mut self,
             buf: &'a mut [u8],
-        ) -> [ReadExactFuture<'a, Self>]
+        ) -> ReadExactFuture<'a, Self>
         where
             Self: Unpin,
         {
@@ -373,7 +372,6 @@ extension_trait! {
             Chain { first: self, second: next, done_first: false }
         }
     }
-}
 
 impl<T: Read + ?Sized> ReadExt for T {}
 

src/io/seek/mod.rs

@@ -6,7 +6,6 @@ use crate::io::SeekFrom;
 
 pub use futures_io::AsyncSeek as Seek;
 
-extension_trait! {
     #[doc = r#"
         Extension methods for [`Seek`].
 
@@ -40,13 +39,12 @@ extension_trait! {
         fn seek(
             &mut self,
             pos: SeekFrom,
-        ) -> [SeekFuture<'_, Self>]
+        ) -> SeekFuture<'_, Self>
         where
             Self: Unpin,
         {
             SeekFuture { seeker: self, pos }
         }
     }
-}
 
 impl<T: Seek + ?Sized> SeekExt for T {}

src/io/write/mod.rs

@@ -14,7 +14,6 @@ use crate::io::{self, IoSlice};
 
 pub use futures_io::AsyncWrite as Write;
 
-extension_trait! {
     #[doc = r#"
         Extension methods for [`Write`].
 
@@ -49,7 +48,7 @@ extension_trait! {
         fn write<'a>(
             &'a mut self,
             buf: &'a [u8],
-        ) -> [WriteFuture<'a, Self>]
+        ) -> WriteFuture<'a, Self>
         where
             Self: Unpin,
         {
@@ -75,7 +74,7 @@ extension_trait! {
             # Ok(()) }) }
             ```
         "#]
-        fn flush(&mut self) -> [FlushFuture<'_, Self>]
+        fn flush(&mut self) -> FlushFuture<'_, Self>
         where
             Self: Unpin,
         {
@@ -97,7 +96,7 @@ extension_trait! {
         fn write_vectored<'a>(
             &'a mut self,
             bufs: &'a [IoSlice<'a>],
-        ) -> [WriteVectoredFuture<'a, Self>]
+        ) -> WriteVectoredFuture<'a, Self>
         where
             Self: Unpin,
         {
@@ -133,7 +132,7 @@ extension_trait! {
         fn write_all<'a>(
             &'a mut self,
             buf: &'a [u8],
-        ) -> [WriteAllFuture<'a, Self>]
+        ) -> WriteAllFuture<'a, Self>
         where
             Self: Unpin,
         {
@@ -170,7 +169,7 @@ extension_trait! {
         fn write_fmt<'a>(
             &'a mut self,
             fmt: std::fmt::Arguments<'_>,
-        ) -> [WriteFmtFuture<'a, Self>]
+        ) -> WriteFmtFuture<'a, Self>
         where
             Self: Unpin,
         {
@@ -184,6 +183,5 @@ extension_trait! {
             WriteFmtFuture { writer: self, res: Some(res), buffer: None, amt: 0 }
         }
     }
-}
 
 impl<T: Write + ?Sized> WriteExt for T {}