1 files changed, 84 insertions, 0 deletions
diff --git a/vendor/futures-util/src/stream/try_stream/try_flatten.rs b/vendor/futures-util/src/stream/try_stream/try_flatten.rs
new file mode 100644
index 000000000..4fc04a07b
--- /dev/null
+++ b/vendor/futures-util/src/stream/try_stream/try_flatten.rs
@@ -0,0 +1,84 @@
+use core::pin::Pin;
+use futures_core::ready;
+use futures_core::stream::{FusedStream, Stream, TryStream};
+use futures_core::task::{Context, Poll};
+#[cfg(feature = "sink")]
+use futures_sink::Sink;
+use pin_project_lite::pin_project;
+
+pin_project! {
+    /// Stream for the [`try_flatten`](super::TryStreamExt::try_flatten) method.
+    #[derive(Debug)]
+    #[must_use = "streams do nothing unless polled"]
+    pub struct TryFlatten<St>
+    where
+        St: TryStream,
+    {
+        #[pin]
+        stream: St,
+        #[pin]
+        next: Option<St::Ok>,
+    }
+}
+
+impl<St> TryFlatten<St>
+where
+    St: TryStream,
+    St::Ok: TryStream,
+    <St::Ok as TryStream>::Error: From<St::Error>,
+{
+    pub(super) fn new(stream: St) -> Self {
+        Self { stream, next: None }
+    }
+
+    delegate_access_inner!(stream, St, ());
+}
+
+impl<St> FusedStream for TryFlatten<St>
+where
+    St: TryStream + FusedStream,
+    St::Ok: TryStream,
+    <St::Ok as TryStream>::Error: From<St::Error>,
+{
+    fn is_terminated(&self) -> bool {
+        self.next.is_none() && self.stream.is_terminated()
+    }
+}
+
+impl<St> Stream for TryFlatten<St>
+where
+    St: TryStream,
+    St::Ok: TryStream,
+    <St::Ok as TryStream>::Error: From<St::Error>,
+{
+    type Item = Result<<St::Ok as TryStream>::Ok, <St::Ok as TryStream>::Error>;
+
+    fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
+        let mut this = self.project();
+
+        Poll::Ready(loop {
+            if let Some(s) = this.next.as_mut().as_pin_mut() {
+                if let Some(item) = ready!(s.try_poll_next(cx)?) {
+                    break Some(Ok(item));
+                } else {
+                    this.next.set(None);
+                }
+            } else if let Some(s) = ready!(this.stream.as_mut().try_poll_next(cx)?) {
+                this.next.set(Some(s));
+            } else {
+                break None;
+            }
+        })
+    }
+}
+
+// Forwarding impl of Sink from the underlying stream
+#[cfg(feature = "sink")]
+impl<S, Item> Sink<Item> for TryFlatten<S>
+where
+    S: TryStream + Sink<Item>,
+{
+    type Error = <S as Sink<Item>>::Error;
+
+    delegate_sink!(stream, Item);
+}