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-rw-r--r--vendor/futures-util/src/sink/drain.rs53
1 files changed, 53 insertions, 0 deletions
diff --git a/vendor/futures-util/src/sink/drain.rs b/vendor/futures-util/src/sink/drain.rs
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+++ b/vendor/futures-util/src/sink/drain.rs
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+use super::assert_sink;
+use crate::never::Never;
+use core::marker::PhantomData;
+use core::pin::Pin;
+use futures_core::task::{Context, Poll};
+use futures_sink::Sink;
+
+/// Sink for the [`drain`] function.
+#[derive(Debug)]
+#[must_use = "sinks do nothing unless polled"]
+pub struct Drain<T> {
+ marker: PhantomData<T>,
+}
+
+/// Create a sink that will just discard all items given to it.
+///
+/// Similar to [`io::Sink`](::std::io::Sink).
+///
+/// # Examples
+///
+/// ```
+/// # futures::executor::block_on(async {
+/// use futures::sink::{self, SinkExt};
+///
+/// let mut drain = sink::drain();
+/// drain.send(5).await?;
+/// # Ok::<(), futures::never::Never>(()) }).unwrap();
+/// ```
+pub fn drain<T>() -> Drain<T> {
+ assert_sink::<T, Never, _>(Drain { marker: PhantomData })
+}
+
+impl<T> Unpin for Drain<T> {}
+
+impl<T> Sink<T> for Drain<T> {
+ type Error = Never;
+
+ fn poll_ready(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
+ Poll::Ready(Ok(()))
+ }
+
+ fn start_send(self: Pin<&mut Self>, _item: T) -> Result<(), Self::Error> {
+ Ok(())
+ }
+
+ fn poll_flush(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
+ Poll::Ready(Ok(()))
+ }
+
+ fn poll_close(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
+ Poll::Ready(Ok(()))
+ }
+}