In most QObjectPrivate-subclasses, the Q_DECLARE_PUBLIC macro is used in
the private segment of the class declaration. In that case, the q_ptr
becomes a private member of the private class, and then the
QObjectPrivate::connect function can no longer be used, as it needs to
access the d_ptr.
Fix this by declaring QObjectPrivate, and the static-assert-helper, as
friends of the class using the Q_DECLARE_PUBLIC macro.
Adapt the QObject test by moving the Q_DECLARE_PUBLIC macro into
the private section of the test-private, and add a compile test.
Pick-to: 6.5 6.5.0
Change-Id: Ifc04be3b305221e138b1e08bb3a3838d871f4fcb
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Axel Spoerl <axel.spoerl@qt.io>
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
4f02973e2f