#include <string>
#include <iostream>
#include <ostream>
#include <sstream>

using namespace std;

#pragma once

class person
{
  private:
    string name;
    int age;
  public:
    person(){};

    person(const string name, int age): name(name), age(age){};
    string as_string() const;

    void populate_data();

    // you can define and declare in a header too:
    inline int dummy_function() { return 42; };

    // this is what allows us to do cout << my_person;
    friend ostream & operator<<(ostream & os, const person & e);
};