Method is_signed

cpp/src/arrow/type.h:577–577

template <typename DERIVED, Type::type TYPE_ID, typename C_TYPE>
class IntegerTypeImpl : public detail::CTypeImpl<DERIVED, IntegerType, TYPE_ID, C_TYPE> {
  bool is_signed() const override { return std::is_signed<C_TYPE>::value; }
};

}  // namespace detail