1 files changed, 12 insertions, 22 deletions

diff --git a/tokio/src/io/util/read_until.rs b/tokio/src/io/util/read_until.rs
index 78dac8c2..3599cff3 100644
--- a/tokio/src/io/util/read_until.rs
+++ b/tokio/src/io/util/read_until.rs
@@ -1,12 +1,14 @@
 use crate::io::AsyncBufRead;
 
+use pin_project_lite::pin_project;
 use std::future::Future;
 use std::io;
+use std::marker::PhantomPinned;
 use std::mem;
 use std::pin::Pin;
 use std::task::{Context, Poll};
 
-cfg_io_util! {
+pin_project! {
     /// Future for the [`read_until`](crate::io::AsyncBufReadExt::read_until) method.
     /// The delimeter is included in the resulting vector.
     #[derive(Debug)]
@@ -15,9 +17,12 @@ cfg_io_util! {
         reader: &'a mut R,
         delimeter: u8,
         buf: &'a mut Vec<u8>,
-        /// The number of bytes appended to buf. This can be less than buf.len() if
-        /// the buffer was not empty when the operation was started.
+        // The number of bytes appended to buf. This can be less than buf.len() if
+        // the buffer was not empty when the operation was started.
         read: usize,
+        // Make this future `!Unpin` for compatibility with async trait methods.
+        #[pin]
+        _pin: PhantomPinned,
     }
 }
 
@@ -34,6 +39,7 @@ where
         delimeter,
         buf,
         read: 0,
+        _pin: PhantomPinned,
     }
 }
 
@@ -66,24 +72,8 @@ pub(super) fn read_until_internal<R: AsyncBufRead + ?Sized>(
 impl<R: AsyncBufRead + ?Sized + Unpin> Future for ReadUntil<'_, R> {
     type Output = io::Result<usize>;
 
-    fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
-        let Self {
-            reader,
-            delimeter,
-            buf,
-            read,
-        } = &mut *self;
-        read_until_internal(Pin::new(reader), cx, *delimeter, buf, read)
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn assert_unpin() {
-        use std::marker::PhantomPinned;
-        crate::is_unpin::<ReadUntil<'_, PhantomPinned>>();
+    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
+        let me = self.project();
+        read_until_internal(Pin::new(*me.reader), cx, *me.delimeter, me.buf, me.read)
     }
 }