Method operator<

include/ceres/internal/fixed_array.h:319–322

  }

  friend bool operator<(const FixedArray& lhs, const FixedArray& rhs) {
    return std::lexicographical_compare(
        lhs.begin(), lhs.end(), rhs.begin(), rhs.end());
  }

  friend bool operator>(const FixedArray& lhs, const FixedArray& rhs) {
    return rhs < lhs;