QObject selfdestruction aware container

Question

Is there a Qt container, that is aware of the destroyed signal of QObject and removes the element if an element was destroyed?

I.e. like this:

QObject *obj1 = new MyObject();
QObject *obj2 = new MyObject();
QObjectContainer c;
c.add(obj1);
c.add(obj2);
qDebug() << c.size(); // Prints 2
delete obj1;
qDebug() << c.size(); // Prints 1

Wait, you have a flaw in your idea. If you delete an object, how would you find its index in the array? You'd need to perform a full search each time. Think about it, it can't be implemented in any reasonable way. Even if your array catches the `destroyed()` signal, it gets only the address of the pointer, not its index in the array. You'll need to search it by value. The performance would be awful. — sashoalm, Mar 17 '15 at 13:44

score 1 · Accepted Answer · answered Mar 17 '15 at 12:44

1

You can do it yourself by catching signal destroyed() inside container-derived class.

P.S. No Qt class does this, AFAIK.

answered Mar 17 '15 at 12:44

Matt

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score 0 · Answer 2 · answered Mar 17 '15 at 12:22

0

QPointer will auto clear itself when the object pointed to is deleted

answered Mar 17 '15 at 12:22

ratchet freak

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Well thats fine bit is there a list which will remove the QPointer if the contained object pointed to is deleted. – ManuelSchneid3r Mar 17 '15 at 12:29
@ManuelSchneid3r you can do some bookkeeping during iteration, though a indexed list is probably not a good idea instead a set-like container would be better. – ratchet freak Mar 17 '15 at 12:31

QObject selfdestruction aware container

2 Answers2