[C++] Store different types in one single vector

single_vector.cpp

// This source code written by Roland Ihasz 
#include <iostream>
#include <vector>
#include <string>

class User_data
{
public:
	User_data(int i, std::string fn, std::string sn, std::string d, double w)
		: id(i), fname(fn), sname(sn), dob(d), weight(w) { }

	int id;
	std::string fname;
	std::string sname;
	std::string dob;
	double weight;
};

int main()
{
	std::vector<User_data> single_vector;
	int n, id_number;
	std::string firtsname;
	std::string surname;
	std::string dateofbirth;
	double weight;
	std::cout << "How many records you want to create?: ";
	std::cin >> n;
	for(auto j = 0; j < n; ++j)
	{
		std::cout << "Record Number: " << j + 1 << std::endl;
		std::cout << "ID: ";
		std::cin >> id_number;
		std::cout << "Firts Name: ";
		std::cin >> firtsname;
		std::cout << "Surname: ";
		std::cin >> surname;
		std::cout << "Date of Birth (MM/DD/YYYY): ";
		std::cin >> dateofbirth;
		std::cout << "Weight: ";
		std::cin >> weight;
		std::cout << std::endl;
		single_vector.push_back(User_data(id_number, firtsname, surname, dateofbirth, weight));
	}
	std::cout << "Listing..." << std::endl;
	for(unsigned int i = 0; i < single_vector.size(); ++i)
	{
		std::cout << single_vector[i].id << " " << single_vector[i].fname << " "
			  << single_vector[i].sname << " " << single_vector[i].dob << " "
			  << single_vector[i].weight << std::endl;
	}
	return 0;
}