Store QList<Custom> in QVariant - c++

Question

I have a class defined as this:
cdataentry.h:
#ifndef CDATAENTRY_H
#define CDATAENTRY_H
#include <QObject>
#include <QString>
#include <QVariant>
#include <QtOpcUa>
#include <QMetaType>
#include <cnodetype.h>
#include <cdatastatus.h>
/**
* #brief A class providing data and methods to describe a single OPCUA ua
* node in the user input table.
*/
class CDataEntry : public QObject
{
Q_OBJECT
public:
CDataEntry(const QString& np, QObject* parent = nullptr);
~CDataEntry();
QString nodePath() const;
private:
/**
* #brief Obsolute path to the node on the MDE server
*/
const QString m_nodePath;
};
Q_DECLARE_METATYPE(CDataEntry); // to be able to store it in QVariant.
#endif // CDATAENTRY_H
I am trying to store a QList<CDataEntry> object in a QVariant. For that end, I have provided the Q_DECLARE_METATYPE(CDataEntry);
The problem is that the code doesnt compile, what I get is:
error: no matching function for call to 'QVariant::QVariant(QList<CDataEntry>&)'
What am I missing here?

Answer 1

You need to add default constructor, copy constructor and copy/assignment operator to your QObject subclass.
Like this:
CDataEntry& operator=(const CDataEntry&){}
CDataEntry(QObject* parent = nullptr):QObject(parent){}
CDataEntry(const CDataEntry&){}
//...
CDataEntry(const QString& np, QObject* parent = nullptr)
after that you can use it in QVariant like that:
CDataEntry test;
QList<CDataEntry> list;
list.append(test);
QVariant var = QVariant::fromValue<QList<CDataEntry>>( list );
auto t = var.value<QList<CDataEntry>>();
qDebug() << t.first().nodePath();