1 files changed, 45 insertions, 0 deletions
diff --git a/tokio/src/stream/any.rs b/tokio/src/stream/any.rs
new file mode 100644
index 00000000..f2ecad5e
--- /dev/null
+++ b/tokio/src/stream/any.rs
@@ -0,0 +1,45 @@
+use crate::stream::Stream;
+
+use core::future::Future;
+use core::pin::Pin;
+use core::task::{Context, Poll};
+
+/// Future for the [`any`](super::StreamExt::any) method.
+#[derive(Debug)]
+#[must_use = "futures do nothing unless you `.await` or poll them"]
+pub struct AnyFuture<'a, St: ?Sized, F> {
+    stream: &'a mut St,
+    f: F,
+}
+
+impl<'a, St: ?Sized, F> AnyFuture<'a, St, F> {
+    pub(super) fn new(stream: &'a mut St, f: F) -> Self {
+        Self { stream, f }
+    }
+}
+
+impl<St: ?Sized + Unpin, F> Unpin for AnyFuture<'_, St, F> {}
+
+impl<St, F> Future for AnyFuture<'_, St, F>
+where
+    St: ?Sized + Stream + Unpin,
+    F: FnMut(St::Item) -> bool,
+{
+    type Output = bool;
+
+    fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
+        let next = futures_core::ready!(Pin::new(&mut self.stream).poll_next(cx));
+
+        match next {
+            Some(v) => {
+                if (&mut self.f)(v) {
+                    Poll::Ready(true)
+                } else {
+                    cx.waker().wake_by_ref();
+                    Poll::Pending
+                }
+            }
+            None => Poll::Ready(false),
+        }
+    }
+}