io: remove poll_{read,write}_buf from traits (#2882)

These functions have object safety issues. It also has been decided to
avoid vectored operations on the I/O traits. A later PR will bring back
vectored operations on specific types that support them.

Refs: #2879, #2716

1 files changed, 0 insertions, 38 deletions

diff --git a/tokio/src/io/util/read_buf.rs b/tokio/src/io/util/read_buf.rs
deleted file mode 100644
index 6ee3d249..00000000
--- a/tokio/src/io/util/read_buf.rs
+++ /dev/null
@@ -1,38 +0,0 @@
-use crate::io::AsyncRead;
-
-use bytes::BufMut;
-use std::future::Future;
-use std::io;
-use std::pin::Pin;
-use std::task::{Context, Poll};
-
-pub(crate) fn read_buf<'a, R, B>(reader: &'a mut R, buf: &'a mut B) -> ReadBuf<'a, R, B>
-where
-    R: AsyncRead + Unpin,
-    B: BufMut,
-{
-    ReadBuf { reader, buf }
-}
-
-cfg_io_util! {
-    /// Future returned by [`read_buf`](crate::io::AsyncReadExt::read_buf).
-    #[derive(Debug)]
-    #[must_use = "futures do nothing unless you `.await` or poll them"]
-    pub struct ReadBuf<'a, R, B> {
-        reader: &'a mut R,
-        buf: &'a mut B,
-    }
-}
-
-impl<R, B> Future for ReadBuf<'_, R, B>
-where
-    R: AsyncRead + Unpin,
-    B: BufMut,
-{
-    type Output = io::Result<usize>;
-
-    fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<usize>> {
-        let me = &mut *self;
-        Pin::new(&mut *me.reader).poll_read_buf(cx, me.buf)
-    }
-}