1 files changed, 48 insertions, 0 deletions
diff --git a/third_party/rust/futures-0.1.31/src/stream/iter_ok.rs b/third_party/rust/futures-0.1.31/src/stream/iter_ok.rs
new file mode 100644
index 0000000000..9c8d871399
--- /dev/null
+++ b/third_party/rust/futures-0.1.31/src/stream/iter_ok.rs
@@ -0,0 +1,48 @@
+use core::marker;
+
+use {Async, Poll};
+use stream::Stream;
+
+/// A stream which is just a shim over an underlying instance of `Iterator`.
+///
+/// This stream will never block and is always ready.
+#[derive(Debug)]
+#[must_use = "streams do nothing unless polled"]
+pub struct IterOk<I, E> {
+    iter: I,
+    _marker: marker::PhantomData<fn() -> E>,
+}
+
+/// Converts an `Iterator` into a `Stream` which is always ready
+/// to yield the next value.
+///
+/// Iterators in Rust don't express the ability to block, so this adapter
+/// simply always calls `iter.next()` and returns that.
+///
+/// ```rust
+/// use futures::*;
+///
+/// let mut stream = stream::iter_ok::<_, ()>(vec![17, 19]);
+/// assert_eq!(Ok(Async::Ready(Some(17))), stream.poll());
+/// assert_eq!(Ok(Async::Ready(Some(19))), stream.poll());
+/// assert_eq!(Ok(Async::Ready(None)), stream.poll());
+/// ```
+pub fn iter_ok<I, E>(i: I) -> IterOk<I::IntoIter, E>
+    where I: IntoIterator,
+{
+    IterOk {
+        iter: i.into_iter(),
+        _marker: marker::PhantomData,
+    }
+}
+
+impl<I, E> Stream for IterOk<I, E>
+    where I: Iterator,
+{
+    type Item = I::Item;
+    type Error = E;
+
+    fn poll(&mut self) -> Poll<Option<I::Item>, E> {
+        Ok(Async::Ready(self.iter.next()))
+    }
+}