1 files changed, 337 insertions, 0 deletions
diff --git a/third_party/rust/futures-util/src/lib.rs b/third_party/rust/futures-util/src/lib.rs
new file mode 100644
index 0000000000..9a10c93c9a
--- /dev/null
+++ b/third_party/rust/futures-util/src/lib.rs
@@ -0,0 +1,337 @@
+//! Combinators and utilities for working with `Future`s, `Stream`s, `Sink`s,
+//! and the `AsyncRead` and `AsyncWrite` traits.
+
+#![cfg_attr(feature = "write-all-vectored", feature(io_slice_advance))]
+#![cfg_attr(not(feature = "std"), no_std)]
+#![warn(
+    missing_debug_implementations,
+    missing_docs,
+    rust_2018_idioms,
+    single_use_lifetimes,
+    unreachable_pub
+)]
+#![doc(test(
+    no_crate_inject,
+    attr(
+        deny(warnings, rust_2018_idioms, single_use_lifetimes),
+        allow(dead_code, unused_assignments, unused_variables)
+    )
+))]
+#![cfg_attr(docsrs, feature(doc_cfg))]
+
+#[cfg(all(feature = "bilock", not(feature = "unstable")))]
+compile_error!("The `bilock` feature requires the `unstable` feature as an explicit opt-in to unstable features");
+
+#[cfg(feature = "alloc")]
+extern crate alloc;
+
+// Macro re-exports
+pub use futures_core::ready;
+pub use pin_utils::pin_mut;
+
+#[cfg(feature = "async-await")]
+#[macro_use]
+mod async_await;
+#[cfg(feature = "async-await")]
+#[doc(hidden)]
+pub use self::async_await::*;
+
+// Not public API.
+#[cfg(feature = "async-await")]
+#[doc(hidden)]
+pub mod __private {
+    pub use crate::*;
+    pub use core::{
+        option::Option::{self, None, Some},
+        pin::Pin,
+        result::Result::{Err, Ok},
+    };
+
+    pub mod async_await {
+        pub use crate::async_await::*;
+    }
+}
+
+#[cfg(feature = "sink")]
+macro_rules! delegate_sink {
+    ($field:ident, $item:ty) => {
+        fn poll_ready(
+            self: core::pin::Pin<&mut Self>,
+            cx: &mut core::task::Context<'_>,
+        ) -> core::task::Poll<Result<(), Self::Error>> {
+            self.project().$field.poll_ready(cx)
+        }
+
+        fn start_send(self: core::pin::Pin<&mut Self>, item: $item) -> Result<(), Self::Error> {
+            self.project().$field.start_send(item)
+        }
+
+        fn poll_flush(
+            self: core::pin::Pin<&mut Self>,
+            cx: &mut core::task::Context<'_>,
+        ) -> core::task::Poll<Result<(), Self::Error>> {
+            self.project().$field.poll_flush(cx)
+        }
+
+        fn poll_close(
+            self: core::pin::Pin<&mut Self>,
+            cx: &mut core::task::Context<'_>,
+        ) -> core::task::Poll<Result<(), Self::Error>> {
+            self.project().$field.poll_close(cx)
+        }
+    };
+}
+
+macro_rules! delegate_future {
+    ($field:ident) => {
+        fn poll(
+            self: core::pin::Pin<&mut Self>,
+            cx: &mut core::task::Context<'_>,
+        ) -> core::task::Poll<Self::Output> {
+            self.project().$field.poll(cx)
+        }
+    };
+}
+
+macro_rules! delegate_stream {
+    ($field:ident) => {
+        fn poll_next(
+            self: core::pin::Pin<&mut Self>,
+            cx: &mut core::task::Context<'_>,
+        ) -> core::task::Poll<Option<Self::Item>> {
+            self.project().$field.poll_next(cx)
+        }
+        fn size_hint(&self) -> (usize, Option<usize>) {
+            self.$field.size_hint()
+        }
+    };
+}
+
+#[cfg(feature = "io")]
+#[cfg(feature = "std")]
+macro_rules! delegate_async_write {
+    ($field:ident) => {
+        fn poll_write(
+            self: core::pin::Pin<&mut Self>,
+            cx: &mut core::task::Context<'_>,
+            buf: &[u8],
+        ) -> core::task::Poll<std::io::Result<usize>> {
+            self.project().$field.poll_write(cx, buf)
+        }
+        fn poll_write_vectored(
+            self: core::pin::Pin<&mut Self>,
+            cx: &mut core::task::Context<'_>,
+            bufs: &[std::io::IoSlice<'_>],
+        ) -> core::task::Poll<std::io::Result<usize>> {
+            self.project().$field.poll_write_vectored(cx, bufs)
+        }
+        fn poll_flush(
+            self: core::pin::Pin<&mut Self>,
+            cx: &mut core::task::Context<'_>,
+        ) -> core::task::Poll<std::io::Result<()>> {
+            self.project().$field.poll_flush(cx)
+        }
+        fn poll_close(
+            self: core::pin::Pin<&mut Self>,
+            cx: &mut core::task::Context<'_>,
+        ) -> core::task::Poll<std::io::Result<()>> {
+            self.project().$field.poll_close(cx)
+        }
+    };
+}
+
+#[cfg(feature = "io")]
+#[cfg(feature = "std")]
+macro_rules! delegate_async_read {
+    ($field:ident) => {
+        fn poll_read(
+            self: core::pin::Pin<&mut Self>,
+            cx: &mut core::task::Context<'_>,
+            buf: &mut [u8],
+        ) -> core::task::Poll<std::io::Result<usize>> {
+            self.project().$field.poll_read(cx, buf)
+        }
+
+        fn poll_read_vectored(
+            self: core::pin::Pin<&mut Self>,
+            cx: &mut core::task::Context<'_>,
+            bufs: &mut [std::io::IoSliceMut<'_>],
+        ) -> core::task::Poll<std::io::Result<usize>> {
+            self.project().$field.poll_read_vectored(cx, bufs)
+        }
+    };
+}
+
+#[cfg(feature = "io")]
+#[cfg(feature = "std")]
+macro_rules! delegate_async_buf_read {
+    ($field:ident) => {
+        fn poll_fill_buf(
+            self: core::pin::Pin<&mut Self>,
+            cx: &mut core::task::Context<'_>,
+        ) -> core::task::Poll<std::io::Result<&[u8]>> {
+            self.project().$field.poll_fill_buf(cx)
+        }
+
+        fn consume(self: core::pin::Pin<&mut Self>, amt: usize) {
+            self.project().$field.consume(amt)
+        }
+    };
+}
+
+macro_rules! delegate_access_inner {
+    ($field:ident, $inner:ty, ($($ind:tt)*)) => {
+        /// Acquires a reference to the underlying sink or stream that this combinator is
+        /// pulling from.
+        pub fn get_ref(&self) -> &$inner {
+            (&self.$field) $($ind get_ref())*
+        }
+
+        /// Acquires a mutable reference to the underlying sink or stream that this
+        /// combinator is pulling from.
+        ///
+        /// Note that care must be taken to avoid tampering with the state of the
+        /// sink or stream which may otherwise confuse this combinator.
+        pub fn get_mut(&mut self) -> &mut $inner {
+            (&mut self.$field) $($ind get_mut())*
+        }
+
+        /// Acquires a pinned mutable reference to the underlying sink or stream that this
+        /// combinator is pulling from.
+        ///
+        /// Note that care must be taken to avoid tampering with the state of the
+        /// sink or stream which may otherwise confuse this combinator.
+        pub fn get_pin_mut(self: core::pin::Pin<&mut Self>) -> core::pin::Pin<&mut $inner> {
+            self.project().$field $($ind get_pin_mut())*
+        }
+
+        /// Consumes this combinator, returning the underlying sink or stream.
+        ///
+        /// Note that this may discard intermediate state of this combinator, so
+        /// care should be taken to avoid losing resources when this is called.
+        pub fn into_inner(self) -> $inner {
+            self.$field $($ind into_inner())*
+        }
+    }
+}
+
+macro_rules! delegate_all {
+    (@trait Future $name:ident < $($arg:ident),* > ($t:ty) $(where $($bound:tt)*)*) => {
+        impl<$($arg),*> futures_core::future::Future for $name<$($arg),*> where $t: futures_core::future::Future $(, $($bound)*)* {
+            type Output = <$t as futures_core::future::Future>::Output;
+
+            delegate_future!(inner);
+        }
+    };
+    (@trait FusedFuture $name:ident < $($arg:ident),* > ($t:ty) $(where $($bound:tt)*)*) => {
+        impl<$($arg),*> futures_core::future::FusedFuture for $name<$($arg),*> where $t: futures_core::future::FusedFuture $(, $($bound)*)* {
+            fn is_terminated(&self) -> bool {
+                self.inner.is_terminated()
+            }
+        }
+    };
+    (@trait Stream $name:ident < $($arg:ident),* > ($t:ty) $(where $($bound:tt)*)*) => {
+        impl<$($arg),*> futures_core::stream::Stream for $name<$($arg),*> where $t: futures_core::stream::Stream $(, $($bound)*)* {
+            type Item = <$t as futures_core::stream::Stream>::Item;
+
+            delegate_stream!(inner);
+        }
+    };
+    (@trait FusedStream $name:ident < $($arg:ident),* > ($t:ty) $(where $($bound:tt)*)*) => {
+        impl<$($arg),*> futures_core::stream::FusedStream for $name<$($arg),*> where $t: futures_core::stream::FusedStream $(, $($bound)*)* {
+            fn is_terminated(&self) -> bool {
+                self.inner.is_terminated()
+            }
+        }
+    };
+    (@trait Sink $name:ident < $($arg:ident),* > ($t:ty) $(where $($bound:tt)*)*) => {
+        #[cfg(feature = "sink")]
+        impl<_Item, $($arg),*> futures_sink::Sink<_Item> for $name<$($arg),*> where $t: futures_sink::Sink<_Item> $(, $($bound)*)* {
+            type Error = <$t as futures_sink::Sink<_Item>>::Error;
+
+            delegate_sink!(inner, _Item);
+        }
+    };
+    (@trait Debug $name:ident < $($arg:ident),* > ($t:ty) $(where $($bound:tt)*)*) => {
+        impl<$($arg),*> core::fmt::Debug for $name<$($arg),*> where $t: core::fmt::Debug $(, $($bound)*)* {
+            fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+                core::fmt::Debug::fmt(&self.inner, f)
+            }
+        }
+    };
+    (@trait AccessInner[$inner:ty, ($($ind:tt)*)] $name:ident < $($arg:ident),* > ($t:ty) $(where $($bound:tt)*)*) => {
+        impl<$($arg),*> $name<$($arg),*> $(where $($bound)*)* {
+            delegate_access_inner!(inner, $inner, ($($ind)*));
+        }
+    };
+    (@trait New[|$($param:ident: $paramt:ty),*| $cons:expr] $name:ident < $($arg:ident),* > ($t:ty) $(where $($bound:tt)*)*) => {
+        impl<$($arg),*> $name<$($arg),*> $(where $($bound)*)* {
+            pub(crate) fn new($($param: $paramt),*) -> Self {
+                Self { inner: $cons }
+            }
+        }
+    };
+    ($(#[$attr:meta])* $name:ident<$($arg:ident),*>($t:ty) : $ftrait:ident $([$($targs:tt)*])* $({$($item:tt)*})* $(where $($bound:tt)*)*) => {
+        pin_project_lite::pin_project! {
+            #[must_use = "futures/streams/sinks do nothing unless you `.await` or poll them"]
+            $(#[$attr])*
+            pub struct $name< $($arg),* > $(where $($bound)*)* { #[pin] inner: $t }
+        }
+
+        impl<$($arg),*> $name< $($arg),* > $(where $($bound)*)* {
+            $($($item)*)*
+        }
+
+        delegate_all!(@trait $ftrait $([$($targs)*])* $name<$($arg),*>($t) $(where $($bound)*)*);
+    };
+    ($(#[$attr:meta])* $name:ident<$($arg:ident),*>($t:ty) : $ftrait:ident $([$($ftargs:tt)*])* + $strait:ident $([$($stargs:tt)*])* $(+ $trait:ident $([$($targs:tt)*])*)* $({$($item:tt)*})* $(where $($bound:tt)*)*) => {
+        delegate_all!($(#[$attr])* $name<$($arg),*>($t) : $strait $([$($stargs)*])* $(+ $trait $([$($targs)*])*)* $({$($item)*})* $(where $($bound)*)*);
+
+        delegate_all!(@trait $ftrait $([$($ftargs)*])* $name<$($arg),*>($t) $(where $($bound)*)*);
+    };
+}
+
+pub mod future;
+#[doc(no_inline)]
+pub use crate::future::{Future, FutureExt, TryFuture, TryFutureExt};
+
+pub mod stream;
+#[doc(no_inline)]
+pub use crate::stream::{Stream, StreamExt, TryStream, TryStreamExt};
+
+#[cfg(feature = "sink")]
+#[cfg_attr(docsrs, doc(cfg(feature = "sink")))]
+pub mod sink;
+#[cfg(feature = "sink")]
+#[doc(no_inline)]
+pub use crate::sink::{Sink, SinkExt};
+
+pub mod task;
+
+pub mod never;
+
+#[cfg(feature = "compat")]
+#[cfg_attr(docsrs, doc(cfg(feature = "compat")))]
+pub mod compat;
+
+#[cfg(feature = "io")]
+#[cfg_attr(docsrs, doc(cfg(feature = "io")))]
+#[cfg(feature = "std")]
+pub mod io;
+#[cfg(feature = "io")]
+#[cfg(feature = "std")]
+#[doc(no_inline)]
+pub use crate::io::{
+    AsyncBufRead, AsyncBufReadExt, AsyncRead, AsyncReadExt, AsyncSeek, AsyncSeekExt, AsyncWrite,
+    AsyncWriteExt,
+};
+
+#[cfg(feature = "alloc")]
+pub mod lock;
+
+#[cfg(not(futures_no_atomic_cas))]
+#[cfg(feature = "alloc")]
+mod abortable;
+
+mod fns;
+mod unfold_state;