{"ast_node_type":"variable","tokens":[{"end":64,"kind":"keyword","start":0,"text":"if"}]}
                        if let Some((_, index_ty, element_ty)) =
                    for (base_t, _) in self.autoderef(base.span, base_t).silence_errors() {
                            self.find_and_report_unsatisfied_index_impl(base, base_t)