String in objects when working with files

Question

I'm trying to write objects that contaings strings into files and after that wants to read this information into objects. It's works fine until the end of program. As I understand error in strings. Program doesn't with this type. If I change them to array of chars it works. Can I work with strings in this program&

#include <iostream>
#include <Windows.h>
#include <fstream>
#include <string>
using namespace std;

class FileWorkers;
class Workers;

class Worker
{
protected:
    string name;
    string date_of_birth;
    string post;
public:
    Worker(string post = "Loader") : name(""), date_of_birth(""), post(post) {}
    virtual Worker& SetWorkerInfo(string name, string date_of_birth)
    {
        Worker::name = name;
        Worker::date_of_birth = date_of_birth;
        return *this;
    }
    virtual void ShowInfo()
    {
        cout << "Firstname and lastname: " << name << endl;
        cout << "Date of birth: " << date_of_birth << endl;
        cout << "Post:" << post << endl;
    }
    friend ostream& operator<<(ostream&, FileWorkers&);
}loader;
int size_worker = sizeof(Worker);

class FileWorkers
{
    string flname;
    fstream* fl;
public:
    FileWorkers(string flname)
    {
        FileWorkers::flname = flname;
        fl = new fstream();
    }
    ~FileWorkers() {
        fl->close();
        delete fl;
    }
    bool Newfl()
    {
        fl->open(flname, ios::in | ios::out | ios::trunc);
        if (!fl) return false;
        return true;
    }
    bool Readfl(Worker& worker)
    {
        fl->read(reinterpret_cast<char*>(&worker), size_worker);
        if (fl->good()) return true;
        fl->clear();
        return false;
    }
    void Rewfl()
    {
        fl->seekg(0);
        fl->seekp(0);
    }
    void Addfl(Worker worker)
    {
        fl->write(reinterpret_cast<char*>(&worker), size_worker);
        fl->flush();
    }
    string Getflname()
    {
        return this->flname;
    }
};

ostream& operator<<(ostream& out, FileWorkers& fw)
{
    Worker w;
    fw.Rewfl();
    while (fw.Readfl(w)) out << w.name << ' ' << w.date_of_birth << ' ' << w.post << endl;
    return out;
}

int main()
{
    FileWorkers fw("workers.txt");
    if (!fw.Newfl())
    {
        cout << "Error creating file";
        return 1;
    }
    int quan_workers = 1;
    string name, date_of_birth;
    for (int i = 0; i < quan_workers; i++)
    {
        cin >> name >> date_of_birth;
        fw.Addfl(loader.SetWorkerInfo(name, date_of_birth));
    }
    cout << fw << endl;
}

I really don't know how to solve this problem. Yeah, I can change to array of chars, but I want work with string, because it's much easier. Btw, sry for my bad english.