1 files changed, 15 insertions, 0 deletions
diff --git a/third_party/rust/futures-0.1.31/src/future/option.rs b/third_party/rust/futures-0.1.31/src/future/option.rs
new file mode 100644
index 0000000000..1b204d376a
--- /dev/null
+++ b/third_party/rust/futures-0.1.31/src/future/option.rs
@@ -0,0 +1,15 @@
+//! Definition of the `Option` (optional step) combinator
+
+use {Future, Poll, Async};
+
+impl<F, T, E> Future for Option<F> where F: Future<Item=T, Error=E> {
+    type Item = Option<T>;
+    type Error = E;
+
+    fn poll(&mut self) -> Poll<Option<T>, E> {
+        match *self {
+            None => Ok(Async::Ready(None)),
+            Some(ref mut x) => x.poll().map(|x| x.map(Some)),
+        }
+    }
+}