1 files changed, 51 insertions, 0 deletions
diff --git a/vendor/futures-util/src/stream/try_stream/try_concat.rs b/vendor/futures-util/src/stream/try_stream/try_concat.rs
new file mode 100644
index 000000000..58fb6a541
--- /dev/null
+++ b/vendor/futures-util/src/stream/try_stream/try_concat.rs
@@ -0,0 +1,51 @@
+use core::pin::Pin;
+use futures_core::future::Future;
+use futures_core::ready;
+use futures_core::stream::TryStream;
+use futures_core::task::{Context, Poll};
+use pin_project_lite::pin_project;
+
+pin_project! {
+    /// Future for the [`try_concat`](super::TryStreamExt::try_concat) method.
+    #[derive(Debug)]
+    #[must_use = "futures do nothing unless you `.await` or poll them"]
+    pub struct TryConcat<St: TryStream> {
+        #[pin]
+        stream: St,
+        accum: Option<St::Ok>,
+    }
+}
+
+impl<St> TryConcat<St>
+where
+    St: TryStream,
+    St::Ok: Extend<<St::Ok as IntoIterator>::Item> + IntoIterator + Default,
+{
+    pub(super) fn new(stream: St) -> Self {
+        Self { stream, accum: None }
+    }
+}
+
+impl<St> Future for TryConcat<St>
+where
+    St: TryStream,
+    St::Ok: Extend<<St::Ok as IntoIterator>::Item> + IntoIterator + Default,
+{
+    type Output = Result<St::Ok, St::Error>;
+
+    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
+        let mut this = self.project();
+
+        Poll::Ready(Ok(loop {
+            if let Some(x) = ready!(this.stream.as_mut().try_poll_next(cx)?) {
+                if let Some(a) = this.accum {
+                    a.extend(x)
+                } else {
+                    *this.accum = Some(x)
+                }
+            } else {
+                break this.accum.take().unwrap_or_default();
+            }
+        }))
+    }
+}