Add extension traits for io 0.1 -> 0.3 compat

Author: Nemo157

futures-util/src/compat/compat01as03.rs

@@ -11,6 +11,9 @@ use std::pin::Pin;
 use std::task::Waker;
 use futures_sink::Sink as Sink03;
 
+#[cfg(feature = "io-compat")]
+pub use io::{AsyncRead01CompatExt, AsyncWrite01CompatExt};
+
 /// Converts a futures 0.1 Future, Stream, AsyncRead, or AsyncWrite
 /// object to a futures 0.3-compatible version,
 #[derive(Debug)]
@@ -297,6 +300,32 @@ mod io {
     use std::io::Error;
     use tokio_io::{AsyncRead as AsyncRead01, AsyncWrite as AsyncWrite01};
 
+    /// Extension trait for tokio-io [`AsyncRead`](tokio_io::AsyncRead)
+    pub trait AsyncRead01CompatExt: AsyncRead01 {
+        /// Converts a tokio-io [`AsyncRead`](tokio_io::AsyncRead) into a futures-io 0.3
+        /// [`AsyncRead`](futures_io::AsyncRead).
+        fn compat(self) -> Compat01As03<Self>
+        where
+            Self: Sized,
+        {
+            Compat01As03::new(self)
+        }
+    }
+    impl<R: AsyncRead01> AsyncRead01CompatExt for R {}
+
+    /// Extension trait for tokio-io [`AsyncWrite`](tokio_io::AsyncWrite)
+    pub trait AsyncWrite01CompatExt: AsyncWrite01 {
+        /// Converts a tokio-io [`AsyncWrite`](tokio_io::AsyncWrite) into a futures-io 0.3
+        /// [`AsyncWrite`](futures_io::AsyncWrite).
+        fn compat(self) -> Compat01As03<Self>
+        where
+            Self: Sized,
+        {
+            Compat01As03::new(self)
+        }
+    }
+    impl<W: AsyncWrite01> AsyncWrite01CompatExt for W {}
+
     impl<R: AsyncRead01> AsyncRead03 for Compat01As03<R> {
         unsafe fn initializer(&self) -> Initializer {
             // check if `prepare_uninitialized_buffer` needs zeroing

futures-util/src/compat/mod.rs

@@ -8,5 +8,8 @@ pub use self::executor::{Executor01CompatExt, Executor01Future, Executor01As03};
 mod compat01as03;
 pub use self::compat01as03::{Compat01As03, Compat01As03Sink, Future01CompatExt, Stream01CompatExt, Sink01CompatExt};
 
+#[cfg(feature = "io-compat")]
+pub use self::compat01as03::{AsyncRead01CompatExt, AsyncWrite01CompatExt};
+
 mod compat03as01;
 pub use self::compat03as01::Compat;

futures/src/lib.rs

@@ -92,6 +92,12 @@ pub mod compat {
         Stream01CompatExt,
         Sink01CompatExt,
     };
+
+    #[cfg(feature = "io-compat")]
+    pub use futures_util::compat::{
+        AsyncRead01CompatExt,
+        AsyncWrite01CompatExt,
+    };
 }
 
 #[cfg(feature = "std")]