Boost C++ parsing of a CSV

#define BOOST_SPIRIT_DEBUG
#include <iostream>
#include <boost/spirit/include/qi.hpp>
#include <boost/spirit/include/phoenix.hpp>
#include <string>
#include <vector>

namespace qi = boost::spirit::qi;
namespace phx = boost::phoenix;

using std::string;

enum LineItems {
    NAME, AGE, UNUSED
};

struct CsvLine {
    string name;
    int age;
};

using Column = std::string;
using Columns = std::vector<Column>;
using CsvFile = std::vector<CsvLine>;

template<typename It>
struct CsvGrammar: qi::grammar<It, CsvFile(), qi::locals<std::vector<LineItems>>, qi::blank_type> {
    CsvGrammar() :
            CsvGrammar::base_type(start) {
        using namespace qi;

        static const char colsep = ',';

        start = qi::omit[header[qi::_a = qi::_1]] >> eol >> line(_a) % eol;
        header = (lit("Name")[phx::push_back(phx::ref(qi::_val), LineItems::NAME)]
                | lit("Age")[phx::push_back(phx::ref(qi::_val), LineItems::AGE)]
                | column[phx::push_back(phx::ref(qi::_val), LineItems::UNUSED)]) % colsep;
        line = (column % colsep)[phx::bind(&CsvGrammar<It>::convertFunc, this, qi::_1, qi::_r1,
                qi::_val)];
        column = quoted | *~char_(",\n");
        quoted = '"' >> *("\"\"" | ~char_("\"\n")) >> '"';

        BOOST_SPIRIT_DEBUG_NODES((header)(column)(quoted));
    }

    void convertFunc(const std::vector<string>& columns, const std::vector<LineItems>& positions, CsvLine &csvLine) {
        int i =0;
        for (LineItems position : positions) {
            switch(position){
            case NAME:
                csvLine.name = columns[i];
                break;
            case AGE:
                csvLine.age = atoi(columns[i].c_str());
                break;
            }
            i++;
        }
    }
private:
    qi::rule<It, CsvFile(), qi::locals<std::vector<LineItems>>, qi::blank_type> start;
    qi::rule<It, std::vector<LineItems>(), qi::blank_type> header;
    qi::rule<It, CsvLine(std::vector<LineItems>), qi::blank_type> line;
    qi::rule<It, Column(), qi::blank_type> column;
    qi::rule<It, std::string()> quoted;
    qi::rule<It, qi::blank_type> empty;

};

int main() {
    const std::string s = "Surname,Name,Age,\nJohn,Doe,32\nMark,Smith,43";

    auto f(begin(s)), l(end(s));
    CsvGrammar<std::string::const_iterator> p;

    CsvFile parsed;
    bool ok = qi::phrase_parse(f, l, p, qi::blank, parsed);

    if (ok) {
        for (CsvLine line : parsed) {
            std::cout << '[' << line.name << ']' << '[' << line.age << ']';
            std::cout << std::endl;
        }
    } else {
        std::cout << "Parse failed\n";
    }

    if (f != l)
        std::cout << "Remaining unparsed: '" << std::string(f, l) << "'\n";
}