1 files changed, 84 insertions, 0 deletions
diff --git a/vendor/tokio/src/io/util/empty.rs b/vendor/tokio/src/io/util/empty.rs
new file mode 100644
index 000000000..f964d18e6
--- /dev/null
+++ b/vendor/tokio/src/io/util/empty.rs
@@ -0,0 +1,84 @@
+use crate::io::{AsyncBufRead, AsyncRead, ReadBuf};
+
+use std::fmt;
+use std::io;
+use std::pin::Pin;
+use std::task::{Context, Poll};
+
+cfg_io_util! {
+    /// An async reader which is always at EOF.
+    ///
+    /// This struct is generally created by calling [`empty`]. Please see
+    /// the documentation of [`empty()`][`empty`] for more details.
+    ///
+    /// This is an asynchronous version of [`std::io::empty`][std].
+    ///
+    /// [`empty`]: fn@empty
+    /// [std]: std::io::empty
+    pub struct Empty {
+        _p: (),
+    }
+
+    /// Creates a new empty async reader.
+    ///
+    /// All reads from the returned reader will return `Poll::Ready(Ok(0))`.
+    ///
+    /// This is an asynchronous version of [`std::io::empty`][std].
+    ///
+    /// [std]: std::io::empty
+    ///
+    /// # Examples
+    ///
+    /// A slightly sad example of not reading anything into a buffer:
+    ///
+    /// ```
+    /// use tokio::io::{self, AsyncReadExt};
+    ///
+    /// #[tokio::main]
+    /// async fn main() {
+    ///     let mut buffer = String::new();
+    ///     io::empty().read_to_string(&mut buffer).await.unwrap();
+    ///     assert!(buffer.is_empty());
+    /// }
+    /// ```
+    pub fn empty() -> Empty {
+        Empty { _p: () }
+    }
+}
+
+impl AsyncRead for Empty {
+    #[inline]
+    fn poll_read(
+        self: Pin<&mut Self>,
+        _: &mut Context<'_>,
+        _: &mut ReadBuf<'_>,
+    ) -> Poll<io::Result<()>> {
+        Poll::Ready(Ok(()))
+    }
+}
+
+impl AsyncBufRead for Empty {
+    #[inline]
+    fn poll_fill_buf(self: Pin<&mut Self>, _: &mut Context<'_>) -> Poll<io::Result<&[u8]>> {
+        Poll::Ready(Ok(&[]))
+    }
+
+    #[inline]
+    fn consume(self: Pin<&mut Self>, _: usize) {}
+}
+
+impl fmt::Debug for Empty {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.pad("Empty { .. }")
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn assert_unpin() {
+        crate::is_unpin::<Empty>();
+    }
+}