PIMPL w Qt - QSharedDataPointer - destruktor?

mam taki program wykorzystujący PIMPL:
Plik employee.h:

#ifndef EMPLOYEE_H
#define EMPLOYEE_H

#include <QSharedDataPointer>
#include <QString>

class EmployeeData;

class Employee
{
  public:
    Employee();
    Employee(int id, QString name);
    Employee(const Employee &other);

    void setId(int id);
    void setName(QString name);
    int id() const;
    QString name() const;

    Employee& operator=(const Employee &other);

  private:
    QSharedDataPointer<EmployeeData> d;
};
#endif

Plik employee.cpp:

#include "employee.h"

class EmployeeData : public QSharedData
{
  public:
    EmployeeData() : id(-1) { name.clear(); }
    EmployeeData(const EmployeeData &other)
         : QSharedData(other), id(other.id), name(other.name) { }
    ~EmployeeData() { }

    int id;
    QString name;
};

Employee::Employee()
{
  d = new EmployeeData;
}

Employee::Employee(int id, QString name)
{
  d = new EmployeeData;
  setId(id);
  setName(name);
}

Employee::Employee(const Employee &other)
 : d (other.d)
{
}

void Employee::setId(int id)
{
  d->id = id;
}

void Employee::setName(QString name)
{
  d->name = name;
}

int Employee::id() const
{
  return d->id;
}

QString Employee::name() const
{
  return d->name;
}

Employee &Employee::operator=(const Employee &other)
{
  d=other.d;
  return *this;
}

i main.cpp:

#include <QDebug>
#include "employee.h"

int main(int argc, char *argv[])
{
  Employee e1(1001, "Albrecht Durer");
  Employee e2 = e1;
  e1.setName("Hans Holbein");

  qDebug() << e1.name() << e2.name();

  return 0;
}

przy próbie kompilacji, kompilator wywala taki błąd:

g++ -c -pipe -O2 -D_REENTRANT -Wall -W -DQT_NO_DEBUG -DQT_CORE_LIB -DQT_SHARED -I../../../../libqt/mkspecs/linux-g++ -I. -I../../../../libqt/include/QtCore -I../../../../libqt/include -I. -o main.o main.cpp
main.cpp:5: warning: unused parameter 'argc'
main.cpp:5: warning: unused parameter 'argv'
../../../../libqt/include/QtCore/qshareddata.h: In destructor 'QSharedDataPointer<T>::~QSharedDataPointer() [with T = EmployeeData]':
employee.h:10: instantiated from here
../../../../libqt/include/QtCore/qshareddata.h:90: error: invalid use of undefined type 'struct EmployeeData'
employee.h:7: error: forward declaration of 'struct EmployeeData'
../../../../libqt/include/QtCore/qshareddata.h:90: warning: possible problem detected in invocation of delete operator:
../../../../libqt/include/QtCore/qshareddata.h:90: warning: invalid use of undefined type 'struct EmployeeData'
employee.h:7: warning: forward declaration of 'struct EmployeeData'
../../../../libqt/include/QtCore/qshareddata.h:90: note: neither the destructor nor the class-specific operator delete will be called, even if they are declared when the class is defined.
make[1]: *** [main.o] Error 1

Może ktoś wie co jest źle?

Czy ty wiesz po co jest ten QSharedDataPointer? Mam wrażenie, że nie (widzę braki w kodzie)!

Zdefiniuj pusty destruktor (możliwe, że jest problem z wygenerowaniem domyślnego destruktora).