[SOLVED] Q_DECLARE_METATYPE and Qt containers

[frankiefrank]

It's a simple question but not evident from the docs at http://qt-project.org/doc/qt-5/qmetatype.html#Q_DECLARE_METATYPE

Let's say I have a class called MyClass and I want to use QList<MyClass> with QVariant.

Do I need to use only
@
Q_DECLARE_METATYPE(MyClass)
@

or

@
Q_DECLARE_METATYPE(QList<MyClass>)
@
(or a typedef of the above if I can't use templates).

[SGaist]

Hi,

IIRC, Qt has built-in support for that. But nothing beats a test :)

[frankiefrank]

Stay tuned :)

[r1z1]

I'm wondering also. Should be mentioned in the documentation.

So if I want to use MyClass in a QList and if I do that:
@
Q_DECLARE_METATYPE(MyClass)
@

I've got a compile error:
@error C2039: 'qt_metatype_id' : is not a member of 'QMetaTypeId<T>'@

But

• If i do that
  @
  Q_DECLARE_METATYPE(MyClass)
  Q_DECLARE_METATYPE(QList<MyClass>)
  @

No compile error.

Maybe a specific include is missing or the QList declare is the only thing to do?

[frankiefrank]

Tested my code and looks like it works even without specifically using the Q_DECLARE_METATYPE for the QList.

@r1z1 I'm not sure about your problem. Maybe you want to open another thread and post exactly where you are putting the Q_DECLARE_METATYPE line.