Do not return &mut Self

futures-util/src/io/window.rs

@@ -67,16 +67,14 @@ impl<T: AsRef<[u8]>> Window<T> {
 
     /// Changes the range of this window to the range specified.
     ///
-    /// Returns the windows back to chain multiple calls to this method.
-    ///
     /// # Panics
     ///
     /// This method will panic if `range` is out of bounds for the underlying
     /// slice or if [`start_bound()`] of `range` comes after the [`end_bound()`].
     ///
     /// [`start_bound()`]: std::ops::RangeBounds::start_bound
     /// [`end_bound()`]: std::ops::RangeBounds::end_bound
-    pub fn set<R: RangeBounds<usize>>(&mut self, range: R) -> &mut Self {
+    pub fn set<R: RangeBounds<usize>>(&mut self, range: R) {
         let start = match range.start_bound() {
             Bound::Included(n) => *n,
             Bound::Excluded(n) => *n + 1,
@@ -93,7 +91,6 @@ impl<T: AsRef<[u8]>> Window<T> {
 
         self.range.start = start;
         self.range.end = end;
-        self
     }
 }
 

futures/tests/io_window.rs

@@ -3,10 +3,10 @@ use futures::io::Window;
 #[test]
 fn set() {
     let mut buffer = Window::new(&[1, 2, 3]);
-    buffer.set(..3)
-          .set(3..3)
-          .set(3..=2) // == 3..3
-          .set(0..2);
+    buffer.set(..3);
+    buffer.set(3..3);
+    buffer.set(3..=2); // == 3..3
+    buffer.set(0..2);
 
     assert_eq!(buffer.as_ref(), &[1, 2]);
 }