{"ast_node_type":"variable","tokens":[{"end":76,"kind":"keyword","start":0,"text":"let"}]}
                        let ty = fcx.resolve_vars_if_possible(self.cast_ty);
                    if let Some(from_trait) = fcx.tcx.get_diagnostic_item(sym::From) {
                        let expr_ty = fcx.resolve_vars_if_possible(self.expr_ty);