Method signatures

bolt/expression/tests/ExprTest.cpp:1953–1961

  }

  static std::vector<std::shared_ptr<exec::FunctionSignature>> signatures() {
    // T, integer -> T
    return {exec::FunctionSignatureBuilder()
                .typeVariable("T")
                .returnType("T")
                .argumentType("T")
                .argumentType("integer")
                .build()};
  }
};

// Single-argument deterministic functions always receive their argument