Serialising variants - QVector<int>() from value.

[Dariusz]

Hey

And I'm stuck, I have a

QMap<int,QMap<int,QVariant>> as my data structure in my treeView.

I was trying to serialize it but I keep getting >

WARNING: QVariant::save: unable to save type 'QVector<int>' (type id: 1033).

 (kernel\qvariant.cpp:2593, void __cdecl QVariant::save(class QDataStream &) const)

As far as I can tell, I have 7 items in my map and some of them are :

QVector<int> data;
QVariant::fromValue(data);

Other than that I don't see other issues, when I look in debug at the map some of variatns have no value at all and others have (invalid) as flag next to them...

Mhmhmmhmmm....

What did I do ? :- )

---

Kay so I did some digging, looks like I have to register it and somehow implement...but how?

    qRegisterMetaType<QVector<int>>("QVector<int>");

    QMap<int, QVariant> wah;
    wah[0] = QVariant::fromValue(QVector<int>{12, 231, 45, 125, 123, 12, 312, 4, 12});
    qDebug() << wah;

    QByteArray ar;
    QDataStream s(&ar, QIODevice::WriteOnly);
    s << wah;

returns the same error...

---

Tried adding this above main... still no luck...

QDataStream &operator<<(QDataStream &out, const QVector<int> &vec) {
    out << vec.size();
    for (auto &v:vec) {
        out << v;
    }
    return out;
};


int main(int argc, char *argv[]) {

---

Answer :

Needed to add :

qRegisterMetaTypeStreamOperators<QVector<int>>("QVector<int>");

I really wish that Docs would explain that... "easier" or mention it somehow. Took a while to read a whole bunch of info to realize this :/