1 files changed, 12 insertions, 16 deletions

diff --git a/tokio/src/io/util/read_exact.rs b/tokio/src/io/util/read_exact.rs
index 970074aa..1e8150eb 100644
--- a/tokio/src/io/util/read_exact.rs
+++ b/tokio/src/io/util/read_exact.rs
@@ -1,7 +1,9 @@
 use crate::io::{AsyncRead, ReadBuf};
 
+use pin_project_lite::pin_project;
 use std::future::Future;
 use std::io;
+use std::marker::PhantomPinned;
 use std::marker::Unpin;
 use std::pin::Pin;
 use std::task::{Context, Poll};
@@ -18,10 +20,11 @@ where
     ReadExact {
         reader,
         buf: ReadBuf::new(buf),
+        _pin: PhantomPinned,
     }
 }
 
-cfg_io_util! {
+pin_project! {
     /// Creates a future which will read exactly enough bytes to fill `buf`,
     /// returning an error if EOF is hit sooner.
     ///
@@ -31,6 +34,9 @@ cfg_io_util! {
     pub struct ReadExact<'a, A: ?Sized> {
         reader: &'a mut A,
         buf: ReadBuf<'a>,
+        // Make this future `!Unpin` for compatibility with async trait methods.
+        #[pin]
+        _pin: PhantomPinned,
     }
 }
 
@@ -44,30 +50,20 @@ where
 {
     type Output = io::Result<usize>;
 
-    fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<usize>> {
+    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<usize>> {
+        let mut me = self.project();
+
         loop {
             // if our buffer is empty, then we need to read some data to continue.
-            let rem = self.buf.remaining();
+            let rem = me.buf.remaining();
             if rem != 0 {
-                let me = &mut *self;
                 ready!(Pin::new(&mut *me.reader).poll_read(cx, &mut me.buf))?;
                 if me.buf.remaining() == rem {
                     return Err(eof()).into();
                 }
             } else {
-                return Poll::Ready(Ok(self.buf.capacity()));
+                return Poll::Ready(Ok(me.buf.capacity()));
             }
         }
     }
 }
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn assert_unpin() {
-        use std::marker::PhantomPinned;
-        crate::is_unpin::<ReadExact<'_, PhantomPinned>>();
-    }
-}