Binary Compatibility Workarounds

This page describes some workarounds for keeping binary compatibility in patch releases. You should read the KDE reference: Binary Compatibility Issues with C++.

Specifically, the d-pointer technique is explained in much detail in D-Pointer: What Private Implementation is and how it works.

Declaring a slot for private classes (d-pointer)

Use a Q_PRIVATE_SLOT:

class A: public QObject
{
Q_OBJECT
…
private:
Q_PRIVATE_SLOT(d_func(), void myPrivateSlot())
};

/* in .cpp file */

void APrivate::myPrivateSlot() {…}

#include "moc_a.cpp"

Pitfalls to avoid:

• Don't include `a.moc`, but `moc_a.cpp` in your .cpp file
• Q_PRIVATE_SLOT takes the complete signature of the private slot, not just its name