Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 75 insertions, 0 deletions

diff --git a/third_party/rust/futures-util/src/future/select_all.rs b/third_party/rust/futures-util/src/future/select_all.rs
new file mode 100644
index 0000000000..0a51d0da6c
--- /dev/null
+++ b/third_party/rust/futures-util/src/future/select_all.rs
@@ -0,0 +1,75 @@
+use super::assert_future;
+use crate::future::FutureExt;
+use alloc::vec::Vec;
+use core::iter::FromIterator;
+use core::mem;
+use core::pin::Pin;
+use futures_core::future::Future;
+use futures_core::task::{Context, Poll};
+
+/// Future for the [`select_all`] function.
+#[derive(Debug)]
+#[must_use = "futures do nothing unless you `.await` or poll them"]
+pub struct SelectAll<Fut> {
+    inner: Vec<Fut>,
+}
+
+impl<Fut: Unpin> Unpin for SelectAll<Fut> {}
+
+/// Creates a new future which will select over a list of futures.
+///
+/// The returned future will wait for any future within `iter` to be ready. Upon
+/// completion the item resolved will be returned, along with the index of the
+/// future that was ready and the list of all the remaining futures.
+///
+/// There are no guarantees provided on the order of the list with the remaining
+/// futures. They might be swapped around, reversed, or completely random.
+///
+/// This function is only available when the `std` or `alloc` feature of this
+/// library is activated, and it is activated by default.
+///
+/// # Panics
+///
+/// This function will panic if the iterator specified contains no items.
+pub fn select_all<I>(iter: I) -> SelectAll<I::Item>
+where
+    I: IntoIterator,
+    I::Item: Future + Unpin,
+{
+    let ret = SelectAll { inner: iter.into_iter().collect() };
+    assert!(!ret.inner.is_empty());
+    assert_future::<(<I::Item as Future>::Output, usize, Vec<I::Item>), _>(ret)
+}
+
+impl<Fut> SelectAll<Fut> {
+    /// Consumes this combinator, returning the underlying futures.
+    pub fn into_inner(self) -> Vec<Fut> {
+        self.inner
+    }
+}
+
+impl<Fut: Future + Unpin> Future for SelectAll<Fut> {
+    type Output = (Fut::Output, usize, Vec<Fut>);
+
+    fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
+        let item = self.inner.iter_mut().enumerate().find_map(|(i, f)| match f.poll_unpin(cx) {
+            Poll::Pending => None,
+            Poll::Ready(e) => Some((i, e)),
+        });
+        match item {
+            Some((idx, res)) => {
+                #[allow(clippy::let_underscore_future)]
+                let _ = self.inner.swap_remove(idx);
+                let rest = mem::take(&mut self.inner);
+                Poll::Ready((res, idx, rest))
+            }
+            None => Poll::Pending,
+        }
+    }
+}
+
+impl<Fut: Future + Unpin> FromIterator<Fut> for SelectAll<Fut> {
+    fn from_iter<T: IntoIterator<Item = Fut>>(iter: T) -> Self {
+        select_all(iter)
+    }
+}