{"ast_node_type":"other","tokens":[{"end":98,"kind":"keyword","start":0,"text":"//"}]}
            // The edition of the trimmed span should be the same as `subpat.span`; this will be a
            let trimmed = self.tcx.sess.source_map().span_through_char(subpat.span, final_char);
            // a hard error if the subpattern is of edition >= 2024. We set it manually to be sure: