Исправить код базы данных

#include<iostream>
#include<vector>
#include<conio.h>
#include<string>
using namespace std;
 
 
int main() {
 
enum position { student, teacher, external_worker };
class inf_system {
    //first name, last name, position, telephone, address
    typedef tuple<string, string, position, size_t, string> row_def;
    typedef const row_def * row_def_const_ptr;
    template<size_t idx>
    using type = typename tuple_element<idx, row_def>::type;
    void insert(const string& first_name, const string& last_name,
        const position& position, const size_t& telephone, const string& address);
    template<size_t idx>
    vector<row_def_const_ptr> find(const type<idx>& value) { ... }
    template<size_t idx>
    size_t erase(const type<idx>& value) { ... }
};
    int main() {
        inf_system inf_system;
 
        inf_system.insert("Prokofjev", "Shaldybin", student, 507 - 66 - 87, "Azovska 1, Moskva");
        inf_system.insert("Prokofjev", "Artem", student,  269 - 85 - 85, "Glinky 27, Fevralskoye");
        inf_system.insert("Rusov", "Solomon", teacher,  598 - 87 - 43, "Baumanskaja 11, Takhtamukay");
        inf_system.insert("Dmitrieva", "Alina", teacher,  598 - 21 - 47, "Avanhard 3, Chaplygin");
        inf_system.insert("Gorodnova", "Viktoria", teacher, 517 - 31- 23, "Baumanskaja 43, Takhtamukay");
        auto result = inf_system.find<2>(student);
        print_vector(result);
        auto count = inf_system.erase<1>("Prokofjev"); 
        auto result = inf_system.find<2>(student);
        print_vector(result);
        auto count = inf_system.erase<1>("Prokofjev");
    }
 
    void print_vector(const vector<inf_system::row_def_const_ptr>& vector) {
        for (const auto& r : vector) {
            cout << get<0>(*r) << " " << get<1>(*r) << " " << get<2>(*r) <<
                " " << get<3>(*r) << " " << get<4>(*r) << endl;
        }
    }