{"ast_node_type":"other","tokens":[{"end":80,"kind":"keyword","start":0,"text":"self.infer_expr(args[arg_idx"}]}
            self.infer_expr(args[arg_idx as usize], &expected, ExprIsRead::Yes);
            let expected = Expectation::none(); // FIXME use actual const ty, when that is lowered correctly
            // FIXME: evaluate and unify with the const