Add Clone impl to BufCursor

src/buf/cursor.rs

@@ -534,3 +534,15 @@ impl<'b, B: SeekBuf + ?Sized> DoubleEndedIterator for BufCursor<'b, B> {
 impl<'b, B: SeekBuf + ?Sized> FusedIterator for BufCursor<'b, B> {}
 
 impl<'b, B: SeekBuf + ?Sized> ExactSizeIterator for BufCursor<'b, B> {}
+
+impl<'b, B: SeekBuf + ?Sized> Clone for BufCursor<'b, B> {
+    fn clone(&self) -> Self {
+        Self {
+            buf: self.buf,
+            front_chunk_offset: Cell::new(self.front_chunk_offset.get()),
+            back_chunk_offset: Cell::new(self.back_chunk_offset.get()),
+            front_chunk: Cell::new(self.front_chunk.get()),
+            back_chunk: Cell::new(self.back_chunk.get()),
+        }
+    }
+}

tests/test_cursor.rs

@@ -26,6 +26,24 @@ fn test_iterator() {
     assert_eq!(cursor.next_back(), None);
 }
 
+#[test]
+fn test_clone() {
+    let buf = b"Hello World!".as_slice();
+
+    let mut cursor = buf.cursor();
+
+    assert_eq!(cursor.next(), Some(&b'H'));
+    assert_eq!(cursor.next_back(), Some(&b'!'));
+
+    let mut cursor_clone = cursor.clone();
+
+    assert_eq!(cursor.next(), Some(&b'e'));
+    assert_eq!(cursor.next_back(), Some(&b'd'));
+
+    assert_eq!(cursor_clone.next(), Some(&b'e'));
+    assert_eq!(cursor_clone.next_back(), Some(&b'd'));
+}
+
 #[test]
 fn test_seek() {
     let buf = b"<<< TEXT >>>".as_slice();