Implementing Extend for String in terms of for_each now that that's been added

Author: sunjay

src/string/extend.rs

@@ -10,24 +10,25 @@ impl Extend<char> for String {
         stream: S,
     ) -> Pin<Box<dyn Future<Output = ()> + 'a>> {
         let stream = stream.into_stream();
-        //TODO: Add this back in when size_hint is added to stream
+        //TODO: Add this back in when size_hint is added to Stream/StreamExt
         // let (lower_bound, _) = stream.size_hint();
         // self.reserve(lower_bound);
 
-        //TODO: This can just be: stream.for_each(move |c| self.push(c))
-        Box::pin(stream.fold((), move |(), c| self.push(c)))
+        Box::pin(stream.for_each(move |c| self.push(c)))
     }
 }
 
 impl<'b> Extend<&'b char> for String {
     fn stream_extend<'a, S: IntoStream<Item = &'b char> + 'a>(
         &'a mut self,
-        stream: S,
+        //TODO: Remove the underscore when uncommenting the body of this impl
+        _stream: S,
     ) -> Pin<Box<dyn Future<Output = ()> + 'a>>
     where
         'b: 'a,
     {
-        //TODO: Box::pin(stream.into_stream().copied())
+        //TODO: This can be uncommented when `copied` is added to Stream/StreamExt
+        //Box::pin(stream.into_stream().copied())
         unimplemented!()
     }
 }
@@ -40,8 +41,7 @@ impl<'b> Extend<&'b str> for String {
     where
         'b: 'a,
     {
-        //TODO: This can just be: stream.into_stream().for_each(move |s| self.push_str(s))
-        Box::pin(stream.into_stream().fold((), move |(), s| self.push_str(s)))
+        Box::pin(stream.into_stream().for_each(move |s| self.push_str(s)))
     }
 }
 
@@ -50,12 +50,7 @@ impl Extend<String> for String {
         &'a mut self,
         stream: S,
     ) -> Pin<Box<dyn Future<Output = ()> + 'a>> {
-        //TODO: This can just be: stream.into_stream().for_each(move |s| self.push_str(&s))
-        Box::pin(
-            stream
-                .into_stream()
-                .fold((), move |(), s| self.push_str(&s)),
-        )
+        Box::pin(stream.into_stream().for_each(move |s| self.push_str(&s)))
     }
 }
 
@@ -67,11 +62,6 @@ impl<'b> Extend<Cow<'b, str>> for String {
     where
         'b: 'a,
     {
-        //TODO: This can just be: stream.into_stream().for_each(move |s| self.push_str(&s))
-        Box::pin(
-            stream
-                .into_stream()
-                .fold((), move |(), s| self.push_str(&s)),
-        )
+        Box::pin(stream.into_stream().for_each(move |s| self.push_str(&s)))
     }
 }