Adopt unsafe_op_in_unsafe_fn style
diff --git a/src/rust_vec.rs b/src/rust_vec.rs
index ce79200..9f4484d 100644
--- a/src/rust_vec.rs
+++ b/src/rust_vec.rs
@@ -65,7 +65,7 @@
     }
 
     pub unsafe fn set_len(&mut self, len: usize) {
-        self.as_mut_vec().set_len(len);
+        unsafe { self.as_mut_vec().set_len(len) }
     }
 }