{"ast_node_type":"variable","tokens":[{"end":56,"kind":"keyword","start":0,"text":"let"}]}
                let box_ty = Ty::new_box(tcx, inner_ty);
                let inner_ty = self.next_ty_var(inner.span);
                self.demand_eqtype_pat(span, expected, box_ty, &pat_info.top_info)?;