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Q_DECLARE_SMART_POINTER_METATYPE type restriction
Joel Bodenmann last edited by
I was investigating the idea of storing an
QVariant. This would allow me to put a shared pointer to my custom data int a
QComboBox's data field.
I'm aware of the existence of
QSharedPointer. The data I am working with is only available wrapped into an
std::shared_ptr(data provided by a 3rd party component). This leaves me with the choice of either storing raw pointers or registering my own type for the use with
For this, I've been looking at
Q_DECLARE_SMART_POINTER_METATYPE. The documentation has the following to say about this macro:
This macro makes the smart pointer SmartPointer known to QMetaType as a smart pointer. This makes it possible to put an instance of SmartPointer<T> into a QVariant, if T is a type which inherits QObject.
I'd be interested to know why
Twould be restricted to a type which inherits
Can anybody enlighten me?
Pretty good question. I think it something you should bring to the interest mailing list where the Qt developers/maintainers can be found.
From a short look at the code without understanding the whole stuff I would guess that internally there is only a QObject pointer is stored. So it must be a QObject to track the lifetime.