{"ast_node_type":"other","tokens":[{"end":98,"kind":"keyword","start":0,"text":"//"}]}
                    // Assume both operands are builtin so we can continue inference. No guarantee
                let ret_ty = if self.is_builtin_binop(&lhs_ty, &lhs_ty, op) {
                    // on the correctness, rustc would complain as necessary lang items don't seem