Qt 4 C++ Getting an error when using 3 classes that use each other, error: field `m_Employer' has incomplete type

Question

I'm in desperate need of help and direction. Been trying to get this to compile, but battling due to the fact that there are 3 classes and not hundreds on how the includes/forward declarations should work here.

The error is marked in person.h.

In addition to the error, there is a warning I've marked in main.cpp.

This is a console app.

Thank you in advance.

person.h

#ifndef PERSON_H
#define PERSON_H
#include <QString>

class Employer;

class Person
{
    public:
        Person(QString name);
        QString toString() const;
        void setPosition(Employer newE, Position newP);
        Position getPosition() const;
    private:
        QString m_Name;
        bool m_Employed;
        Position m_Position;
        Employer m_Employer; //--> ERROR: field `m_Employer' has incomplete type.
};

#endif // PERSON_H

person.cpp

#include "employer.h"
#include "position.h"
#include "person.h"


Person::Person(QString name) : m_Name(name), m_Employed(false), m_Position(""), m_Employer("")
{
}



void Person::setPosition(Employer newE, Position newP)
{
    m_Position = newP;
    m_Employed = true;
    m_Employer = newE;
}

Position Person::getPosition()const
{
    return (m_Employed ? m_Position : Position("Professional nose-picker"));
}

QString Person::toString()const
{
    return m_Name + ", Employed: " + (m_Employed ? "Yes" : "No") + ", Position: " + getPosition().toString();
}

employer.h

#ifndef EMPLOYER_H
#define EMPLOYER_H
#include <QString>

//class Position;
//class Person;

class Employer
{
    public:
        Employer(QString name, QString market = "");
        void hire(Person &newHire, Position pos);
        QString toString() const;
    private:
        QString m_Name;
        QString m_Market;
};

#endif // EMPLOYER_H

employer.cpp

#include "employer.h"
#include "person.h"
#include "position.h"


Employer::Employer(QString name, QString market) : m_Name(name), m_Market(market)
{
}

QString Employer::toString()const
{
    return m_Name + (m_Market != "" ? ", Market: " + m_Market : "");
}

void Employer::hire(Person &newHire, Position pos)
{
    newHire.setPosition(*this, pos);
}

position.h

#ifndef POSITION_H
#define POSITION_H
#include <QString>

class Position
{
    public:
        Position(QString name, QString desc = "");
        QString toString() const;
    private:
        QString m_Name;
        QString m_Desc;
};

#endif // POSITION_H

position.cpp

#include "position.h"

Position::Position(QString name, QString desc)
        :m_Name(name), m_Desc(desc)
{}

QString Position::toString()const
{
    return m_Name + (m_Desc != "" ? ", Description: " + m_Desc : "");
}

main.cpp

#include <QtCore/QCoreApplication>
#include <QTextStream>
#include "position.h"
#include "person.h" //--WARNING -> In file included from main.cpp:4:
#include "employer.h"



int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);
    QTextStream cout(stdout);

    Person bob("Bob");
    Employer devCo("Dev Co");

    cout << bob.toString() << endl;
    bob.setPosition(is, Position("Developer", "Software Eng"));
    cout << bob.toString() << endl;
    cout << devCo.toString() << endl;

    return a.exec();
}