#define SHARED

class MyAbstractClass
{
public:
    MyAbstractClass();
    virtual ~MyAbstractClass() {}

    virtual void doSomething() = 0;
};

class MyDerivedClass : public MyAbstractClass
{
public:
    MyDerivedClass();
    ~MyDerivedClass();

    void doSomething();
};

class MyAbstractFactory
{
public:
    MyAbstractFactory();
    virtual ~MyAbstractFactory() {}

#ifdef SHARED
    virtual QSharedPointer<MyAbstractClass> make() = 0;
#else
    virtual MyAbstractClass* make() = 0;
#endif
};

class MyDerivedFactory : public MyAbstractFactory
{
public:
    MyDerivedFactory();
    ~MyDerivedFactory();

#ifdef SHARED
    QSharedPointer<MyAbstractClass> make();
#else
    MyAbstractClass* make();
#endif
};