Implements Clone on Sink combinators where it makes sense.

Author: rubdos

futures-util/src/sink/err_into.rs

@@ -6,7 +6,7 @@ use sink::{SinkExt, SinkMapErr};
 /// A sink combinator to change the error type of a sink.
 ///
 /// This is created by the `Sink::err_into` method.
-#[derive(Debug)]
+#[derive(Clone, Debug)]
 #[must_use = "futures do nothing unless polled"]
 pub struct SinkErrInto<S: Sink, E> {
     sink: SinkMapErr<S, fn(S::SinkError) -> E>,

futures-util/src/sink/fanout.rs

@@ -8,6 +8,7 @@ use futures_sink::{ Sink};
 ///
 /// Backpressure from any downstream sink propagates up, which means that this sink
 /// can only process items as fast as its _slowest_ downstream sink.
+#[derive(Clone)]
 pub struct Fanout<A: Sink, B: Sink> {
     left: A,
     right: B

futures-util/src/sink/map_err.rs

@@ -3,7 +3,7 @@ use futures_core::task;
 use futures_sink::{Sink};
 
 /// Sink for the `Sink::sink_map_err` combinator.
-#[derive(Debug)]
+#[derive(Clone, Debug)]
 #[must_use = "sinks do nothing unless polled"]
 pub struct SinkMapErr<S, F> {
     sink: S,

futures-util/src/sink/with.rs

@@ -7,7 +7,7 @@ use futures_sink::{Sink};
 
 /// Sink for the `Sink::with` combinator, chaining a computation to run *prior*
 /// to pushing a value into the underlying sink.
-#[derive(Debug)]
+#[derive(Clone, Debug)]
 #[must_use = "sinks do nothing unless polled"]
 pub struct With<S, U, Fut, F>
     where S: Sink,
@@ -20,7 +20,7 @@ pub struct With<S, U, Fut, F>
     _phantom: PhantomData<fn(U)>,
 }
 
-#[derive(Debug)]
+#[derive(Clone, Debug)]
 enum State<Fut, T> {
     Empty,
     Process(Fut),