1 files changed, 76 insertions, 0 deletions
diff --git a/third_party/rust/futures-0.1.29/src/stream/future.rs b/third_party/rust/futures-0.1.29/src/stream/future.rs
new file mode 100644
index 0000000000..5b052ee4d3
--- /dev/null
+++ b/third_party/rust/futures-0.1.29/src/stream/future.rs
@@ -0,0 +1,76 @@
+use {Future, Poll, Async};
+use stream::Stream;
+
+/// A combinator used to temporarily convert a stream into a future.
+///
+/// This future is returned by the `Stream::into_future` method.
+#[derive(Debug)]
+#[must_use = "futures do nothing unless polled"]
+pub struct StreamFuture<S> {
+    stream: Option<S>,
+}
+
+pub fn new<S: Stream>(s: S) -> StreamFuture<S> {
+    StreamFuture { stream: Some(s) }
+}
+
+impl<S> StreamFuture<S> {
+    /// Acquires a reference to the underlying stream that this combinator is
+    /// pulling from.
+    ///
+    /// This method returns an `Option` to account for the fact that `StreamFuture`'s
+    /// implementation of `Future::poll` consumes the underlying stream during polling 
+    /// in order to return it to the caller of `Future::poll` if the stream yielded
+    /// an element.
+    pub fn get_ref(&self) -> Option<&S> {
+        self.stream.as_ref()
+    }
+
+    /// Acquires a mutable reference to the underlying stream that this
+    /// combinator is pulling from.
+    ///
+    /// Note that care must be taken to avoid tampering with the state of the
+    /// stream which may otherwise confuse this combinator.
+    ///
+    /// This method returns an `Option` to account for the fact that `StreamFuture`'s
+    /// implementation of `Future::poll` consumes the underlying stream during polling 
+    /// in order to return it to the caller of `Future::poll` if the stream yielded
+    /// an element.
+    pub fn get_mut(&mut self) -> Option<&mut S> {
+        self.stream.as_mut()
+    }
+
+    /// Consumes this combinator, returning the underlying stream.
+    ///
+    /// Note that this may discard intermediate state of this combinator, so
+    /// care should be taken to avoid losing resources when this is called.
+    ///
+    /// This method returns an `Option` to account for the fact that `StreamFuture`'s
+    /// implementation of `Future::poll` consumes the underlying stream during polling 
+    /// in order to return it to the caller of `Future::poll` if the stream yielded
+    /// an element.
+    pub fn into_inner(self) -> Option<S> {
+        self.stream
+    }
+}
+
+impl<S: Stream> Future for StreamFuture<S> {
+    type Item = (Option<S::Item>, S);
+    type Error = (S::Error, S);
+
+    fn poll(&mut self) -> Poll<Self::Item, Self::Error> {
+        let item = {
+            let s = self.stream.as_mut().expect("polling StreamFuture twice");
+            match s.poll() {
+                Ok(Async::NotReady) => return Ok(Async::NotReady),
+                Ok(Async::Ready(e)) => Ok(e),
+                Err(e) => Err(e),
+            }
+        };
+        let stream = self.stream.take().unwrap();
+        match item {
+            Ok(e) => Ok(Async::Ready((e, stream))),
+            Err(e) => Err((e, stream)),
+        }
+    }
+}