1 files changed, 64 insertions, 0 deletions
diff --git a/third_party/rust/futures-0.1.31/src/sink/map_err.rs b/third_party/rust/futures-0.1.31/src/sink/map_err.rs
new file mode 100644
index 0000000000..25c168c071
--- /dev/null
+++ b/third_party/rust/futures-0.1.31/src/sink/map_err.rs
@@ -0,0 +1,64 @@
+use sink::Sink;
+
+use {Poll, StartSend, Stream};
+
+/// Sink for the `Sink::sink_map_err` combinator.
+#[derive(Clone,Debug)]
+#[must_use = "sinks do nothing unless polled"]
+pub struct SinkMapErr<S, F> {
+    sink: S,
+    f: Option<F>,
+}
+
+pub fn new<S, F>(s: S, f: F) -> SinkMapErr<S, F> {
+    SinkMapErr { sink: s, f: Some(f) }
+}
+
+impl<S, E> SinkMapErr<S, E> {
+    /// Get a shared reference to the inner sink.
+    pub fn get_ref(&self) -> &S {
+        &self.sink
+    }
+
+    /// Get a mutable reference to the inner sink.
+    pub fn get_mut(&mut self) -> &mut S {
+        &mut self.sink
+    }
+
+    /// Consumes this combinator, returning the underlying sink.
+    ///
+    /// Note that this may discard intermediate state of this combinator, so
+    /// care should be taken to avoid losing resources when this is called.
+    pub fn into_inner(self) -> S {
+        self.sink
+    }
+}
+
+impl<S, F, E> Sink for SinkMapErr<S, F>
+    where S: Sink,
+          F: FnOnce(S::SinkError) -> E,
+{
+    type SinkItem = S::SinkItem;
+    type SinkError = E;
+
+    fn start_send(&mut self, item: Self::SinkItem) -> StartSend<Self::SinkItem, Self::SinkError> {
+        self.sink.start_send(item).map_err(|e| self.f.take().expect("cannot use MapErr after an error")(e))
+    }
+
+    fn poll_complete(&mut self) -> Poll<(), Self::SinkError> {
+        self.sink.poll_complete().map_err(|e| self.f.take().expect("cannot use MapErr after an error")(e))
+    }
+
+    fn close(&mut self) -> Poll<(), Self::SinkError> {
+        self.sink.close().map_err(|e| self.f.take().expect("cannot use MapErr after an error")(e))
+    }
+}
+
+impl<S: Stream, F> Stream for SinkMapErr<S, F> {
+    type Item = S::Item;
+    type Error = S::Error;
+
+    fn poll(&mut self) -> Poll<Option<S::Item>, S::Error> {
+        self.sink.poll()
+    }
+}