Optimize Iterator:last() for PyList & PyTuple

PyO3 · Jan 29, 2025 · 9a92993 · 9a92993
1 parent f89b5f7
commit 9a92993
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diff --git a/newsfragments/4878.added.md b/newsfragments/4878.added.md
@@ -0,0 +1 @@
+Optimizes `last` for `BoundListIterator`, `BoundTupleIterator` and `BorrowedTupleIterator`
diff --git a/src/types/list.rs b/src/types/list.rs
@@ -750,6 +750,14 @@ impl<'py> Iterator for BoundListIterator<'py> {
             None
         })
     }
+
+    #[inline]
+    fn last(mut self) -> Option<Self::Item>
+    where
+        Self: Sized
+    {
+        self.next_back()
+    }
 }
 
 impl DoubleEndedIterator for BoundListIterator<'_> {

diff --git a/src/types/tuple.rs b/src/types/tuple.rs
@@ -375,6 +375,14 @@ impl<'py> Iterator for BoundTupleIterator<'py> {
         let len = self.len();
         (len, Some(len))
     }
+
+    #[inline]
+    fn last(mut self) -> Option<Self::Item>
+    where
+        Self: Sized
+    {
+        self.next_back()
+    }
 }
 
 impl DoubleEndedIterator for BoundTupleIterator<'_> {
@@ -467,6 +475,14 @@ impl<'a, 'py> Iterator for BorrowedTupleIterator<'a, 'py> {
         let len = self.len();
         (len, Some(len))
     }
+
+    #[inline]
+    fn last(mut self) -> Option<Self::Item>
+    where
+        Self: Sized
+    {
+        self.next_back()
+    }
 }
 
 impl DoubleEndedIterator for BorrowedTupleIterator<'_, '_> {
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1 @@
		Optimizes `last` for `BoundListIterator`, `BoundTupleIterator` and `BorrowedTupleIterator`