1 files changed, 37 insertions, 0 deletions
diff --git a/third_party/rust/tokio-fs/src/file/seek.rs b/third_party/rust/tokio-fs/src/file/seek.rs
new file mode 100644
index 0000000000..0765d3db90
--- /dev/null
+++ b/third_party/rust/tokio-fs/src/file/seek.rs
@@ -0,0 +1,37 @@
+use super::File;
+
+use futures::{Future, Poll};
+
+use std::io;
+
+/// Future returned by `File::seek`.
+#[derive(Debug)]
+pub struct SeekFuture {
+    inner: Option<File>,
+    pos: io::SeekFrom,
+}
+
+impl SeekFuture {
+    pub(crate) fn new(file: File, pos: io::SeekFrom) -> Self {
+        Self {
+            pos,
+            inner: Some(file),
+        }
+    }
+}
+
+impl Future for SeekFuture {
+    type Item = (File, u64);
+    type Error = io::Error;
+
+    fn poll(&mut self) -> Poll<Self::Item, Self::Error> {
+        let pos = try_ready!(
+            self.inner
+                .as_mut()
+                .expect("Cannot poll `SeekFuture` after it resolves")
+                .poll_seek(self.pos)
+        );
+        let inner = self.inner.take().unwrap();
+        Ok((inner, pos).into())
+    }
+}