Method operator()

cpp/src/arrow/flight/sql/server_test.cc:53–56

\brief Asserts that the current DenseUnionScalar equals to given string value

 public:
  /// \brief Asserts that the current DenseUnionScalar equals to given string value
  void operator()(const std::string& string_value) const {
    const auto& scalar = checked_cast<const StringScalar&>(*data.value);
    ASSERT_EQ(string_value, scalar.ToString());
  }

  /// \brief Asserts that the current DenseUnionScalar equals to given bool value
  void operator()(const bool bool_value) const {