sample output from cpp-data-classes program

output.cpp

class DataTable {

    std::int64_t rows;
    std::vector<std::string> names;
    std::vector<std::pair<double, double>> locations;
    std::string table_name;

    public: 

    DataTable() {

    }

    DataTable(const std::int64_t &_rows, const std::vector<std::string> &_names, const std::vector<std::pair<double, double>> &_locations, const std::string &_table_name) : rows(_rows), names(_names), locations(_locations), table_name(_table_name) {

    }

    friend bool operator == (const DataTable &a, const DataTable &b) {
        return a.rows == b.rows && a.names == b.names && a.locations == b.locations && a.table_name == b.table_name;
    }

    friend bool operator != (const DataTable &a, const DataTable &b) {
        return !(a == b);
    }

    friend bool operator < (const DataTable &a, const DataTable &b) {
        return a.rows < b.rows && a.names < b.names && a.locations < b.locations && a.table_name < b.table_name;
    }

    friend bool operator <= (const DataTable &a, const DataTable &b) {
        return !(a > b);
    }

    friend bool operator > (const DataTable &a, const DataTable &b) {
        return a.rows > b.rows && a.names > b.names && a.locations > b.locations && a.table_name > b.table_name;
    }

    friend bool operator >= (const DataTable &a, const DataTable &b) {
        return !(a < b);
    }

    std::int64_t get_rows() {
        return rows;
    }

    void set_rows(const std::int64_t &x) {
        rows = x;
    }

    std::vector<std::string> get_names() {
        return names;
    }

    void set_names(const std::vector<std::string> &x) {
        names = x;
    }

    std::vector<std::pair<double, double>> get_locations() {
        return locations;
    }

    void set_locations(const std::vector<std::pair<double, double>> &x) {
        locations = x;
    }

    std::string get_table_name() {
        return table_name;
    }

    void set_table_name(const std::string &x) {
        table_name = x;
    }

};

std::string to_string(const DataTable &x) {
    return to_string(rows) + " " + to_string(names) + " " + to_string(locations) + " " + to_string(table_name);
}

template<typename U>
U& operator << (U& out, const DataTable &x) {
    return out << ' ' << rows << ' ' << names << ' ' << locations << ' ' << table_name;
}