{"ast_node_type":"other","tokens":[{"end":94,"kind":"keyword","start":0,"text":"self.psess.gated_spans.gate(sym::box_patterns,"}]}
            self.psess.gated_spans.gate(sym::box_patterns, box_span.to(self.prev_token.span));
            let pat = self.parse_pat_with_range_pat(false, None, None)?;
            Ok(PatKind::Box(pat))