Textdatei in c++ Konsolenanwendung auslesen

#include <iostream>
#include "cls.h"
#include <windows.h>
#include <fstream>
#include <fstream>
using namespace std;

int menue1;
void terminkalender();
void terminhinzufuegen();
void terminloeschen();
void terminansehen();
void patientendatenbank();
void patienthinzufuegen();
void patientloeschen();
void patientansehen();
void diagnose();
void beenden();


int main()
{
 cls();
 cout << " -------------------------------\n"
 << " |Arztpraxis Verwaltungsprogramm|\n"
 << " -------------------------------\n\n"
 << "Hauptmenue:\n\n"
 << "1. Terminkalender 3. Diagnosen\n"
 << "2. Patientendatenbank 4. Beenden\n\n";

 cout << "Menuepunkt waehlen:";
 cin >> menue1;

 switch (menue1)
 {
 case 1 : terminkalender();
 break;
 case 2 : patientendatenbank();
 break;
 case 3 : diagnose();
 break;
 case 4 : beenden();
 }

}

void terminkalender()
{
 cls();
 int menuet;
 cout << " -------------------------------\n"
 << " | Terminkalender |\n"
 << " -------------------------------\n\n"
 << "Menue:\n\n"
 << "1. Termin hinzufuegen 3. Termine ansehen\n"
 << "2. Termin loeschen 4. zurueck\n\n";

 cout << "Menuepunkt waehlen:";
 cin >> menuet;

 switch (menuet)
 {
 case 1 : terminhinzufuegen();
 break;
 case 2 : terminloeschen();
 break;
 case 3 : terminansehen();
 break;
 case 4 : main();
 }
}

void terminhinzufuegen()
{
}

void terminloeschen()
{
}

void terminansehen()
{


}


void patientendatenbank()
{
 cls();
 int menued;
 cout << " -------------------------------\n"
 << " | Patientendatenbank |\n"
 << " -------------------------------\n\n"
 << "Menue:\n\n"
 << "1. Patient hinzufuegen 3. Patienten ansehen\n"
 << "2. Patient loeschen 4. zurueck\n\n";

 cout << "Menuepunkt waehlen:";
 cin >> menued;

 switch (menued)
 {
 case 1 : patienthinzufuegen();
 break;
 case 2 : patientloeschen();
 break;
 case 3 : patientansehen();
 break;
 case 4 : main();
 }
}

void patienthinzufuegen()
{


}

void patientloeschen()
{
}

void patientansehen()
{
}

void diagnose()
{
}

void beenden()
{

}