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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 19:33:14 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 19:33:14 +0000
commit36d22d82aa202bb199967e9512281e9a53db42c9 (patch)
tree105e8c98ddea1c1e4784a60a5a6410fa416be2de /third_party/rust/futures-util/src/future/pending.rs
parentInitial commit. (diff)
downloadfirefox-esr-upstream.tar.xz
firefox-esr-upstream.zip
Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'third_party/rust/futures-util/src/future/pending.rs')
-rw-r--r--third_party/rust/futures-util/src/future/pending.rs55
1 files changed, 55 insertions, 0 deletions
diff --git a/third_party/rust/futures-util/src/future/pending.rs b/third_party/rust/futures-util/src/future/pending.rs
new file mode 100644
index 0000000000..b8e28686e1
--- /dev/null
+++ b/third_party/rust/futures-util/src/future/pending.rs
@@ -0,0 +1,55 @@
+use super::assert_future;
+use core::marker;
+use core::pin::Pin;
+use futures_core::future::{FusedFuture, Future};
+use futures_core::task::{Context, Poll};
+
+/// Future for the [`pending()`] function.
+#[derive(Debug)]
+#[must_use = "futures do nothing unless you `.await` or poll them"]
+pub struct Pending<T> {
+ _data: marker::PhantomData<T>,
+}
+
+impl<T> FusedFuture for Pending<T> {
+ fn is_terminated(&self) -> bool {
+ true
+ }
+}
+
+/// Creates a future which never resolves, representing a computation that never
+/// finishes.
+///
+/// The returned future will forever return [`Poll::Pending`].
+///
+/// # Examples
+///
+/// ```ignore
+/// # futures::executor::block_on(async {
+/// use futures::future;
+///
+/// let future = future::pending();
+/// let () = future.await;
+/// unreachable!();
+/// # });
+/// ```
+#[cfg_attr(docsrs, doc(alias = "never"))]
+pub fn pending<T>() -> Pending<T> {
+ assert_future::<T, _>(Pending { _data: marker::PhantomData })
+}
+
+impl<T> Future for Pending<T> {
+ type Output = T;
+
+ fn poll(self: Pin<&mut Self>, _: &mut Context<'_>) -> Poll<T> {
+ Poll::Pending
+ }
+}
+
+impl<T> Unpin for Pending<T> {}
+
+impl<T> Clone for Pending<T> {
+ fn clone(&self) -> Self {
+ pending()
+ }
+}