QxSerializeQDataStream_QSharedPointer

[Kasuax]

The following code fails to compile when QxSerialization is turned off. Qt Serialization takes over and does not understand abstract types. I'm not sure how to turn Qt Serialization off too. It looks like it's too closely baked into the framework and needed for ancillary operations.

Code: Select all

template <typename T>
QDataStream & operator<< (QDataStream & stream, const QSharedPointer<T> & t)
{
{
   qint8 iIsNull = 0;
   stream >> iIsNull;
   if (! iIsNull) { t = QSharedPointer<T>(new T()); stream >> (* t); }
   else { t = QSharedPointer<T>(); }
   return stream;
}

[qxorm]

Hello,

The following code fails to compile when QxSerialization is turned off.

What compilation options have you defined to turn it off ?
I'm not able to reproduce your issue.

[Kasuax]

This was my solution.

Code: Select all

template <typename T>
QDataStream & operator<< (QDataStream & stream, const QSharedPointer<T> & t)
{
   qint8 iIsNull = (t ? 0 : 1);

   if (boost::is_abstract<T>::value)
       iIsNull = 0;

   stream << iIsNull;
   if (t) { stream << (* t); }
   return stream;
}


[Kasuax]

It's not a good solution but it moved me a bit further...

[qxorm]

boost serialization provides more features than Qt serialization.
For abstract classes, boost serialization iterates over all derived classes to check real C++ instance type ==> this is why it works with boost serialization.

With Qt serialization, you can't serialize a pointer to an abstract class for example : you have to cast it to real type before starting the serialization process.