QSettings custom class serialization problem

Hi,

I have a problem with class serialization.
I have two classes (one derived from the other)
I provided operator << for the two classes and all works fine if I use the class separately.
I have a problem when I try to use them in a List containing instances of the two classes: it is used always the << operator of the parent class.

Here's an example.
Two classes (Test2 just adds a QString property to Test):

Code:

class Test : public QObject
{
    Q_OBJECT
public:
    explicit Test(QObject *parent = 0);
    Test(const Test& test);
 
    QString Field_1;
    QString Field_2;
    int Field_3;
};
 
class Test2 : public Test
{
    Q_OBJECT
public:
    explicit Test2(QObject *parent = 0);
    Test2(const Test2& test2);
 
    QString Field_4;
};
 
Test::Test(QObject *parent) :
    QObject(parent)
{
}
 
Test::Test(const Test& test)
{
    Field_1 = test.Field_1;
    Field_2 = test.Field_2;
    Field_3 = test.Field_3;
}
 
Test2::Test2(QObject *parent) :
    Test(parent)
{
}
 
Test2::Test2(const Test2& test2) :
        Test(test2)
{
    Field_4 = test2.Field_4;
}
 
Q_DECLARE_METATYPE(Test)
QDataStream &operator<<(QDataStream &out, const Test &test)
{
    out << test.Field_1 << test.Field_2 << test.Field_3;
    return out;
}
 
QDataStream &operator>>(QDataStream &in, Test &test)
{
    in >> test.Field_1 >> test.Field_2 >> test.Field_3;
    return in;
}
 
Q_DECLARE_METATYPE(Test2)
QDataStream &operator<<(QDataStream &out, const Test2 &test)
{
    out << test.Field_1 << test.Field_2 << test.Field_3 << test.Field_4;
    return out;
}
 
QDataStream &operator>>(QDataStream &in, Test2 &test)
{
    in >> test.Field_1 >> test.Field_2 >> test.Field_3 >> test.Field_4;
    return in;
}

If I put in a List instances of the two class in the ini file I always get just a Test serialization:

Code:

QSettings settings;
 
QList<Test*> list;
 
Test* t = new Test(this);
t->Field_1 = "Field 1";
t->Field_2 = "Field 2";
t->Field_3 = 10;
list.append(t);
 
Test2* t2 = new Test2(this);
t2->Field_1 = "Field 1";
t2->Field_2 = "Field 2";
t2->Field_3 = 10;
t2->Field_4 = "Field 4";
list.append(t2);
 
settings.beginWriteArray("tests");
int index = 0;
foreach (Test* o, list){
    settings.setArrayIndex(index);
    settings.setValue("test", qVariantFromValue(*o));
    index++;
}
settings.endArray();
settings.sync();

Is it normal? How can I correctly serialize that Test2 instance?

Many thanks