[Qt-interest] FW: Iterators and implicitly shared containers

[Ben Swerts]

Sorry about that, Ctrl+Enter is not the key combination you want to use in
Outlook while writing a reply...
> 	>>however, the *it=2; should recognize that the ref 
> count > 1, and
> 	>>do a detach/deep copy as necessary no??
> 	>>
> 	>>Soctt
> 	
> 	This is what I would expect,
> 	but I afraid that you can't achieve it at least with 
> current implementation of iterators/containers sharing in Qt.
> 	
> 	The way to fix your code is to obtain iterator after assignment.
> 	Modification below will produce results you expected, 
> cause detachment will be done when v1.begin() is called.
> 	
> 	If I were you I would try to report the bug. If not 
> fixed it will be good at least to have a special warning in 
> documentation which identifies possible problem.

Due to your comment, I checked the documentation of QVector and then
implicit sharing. It is actually mentioned there!

"Warning: Do not copy an implicitly shared container (QMap, QVector, etc.)
while you are iterating over it using an non-const STL-style iterator."

Well, I have to do it anyway so thanks to Sean I now know that QVector has a
public detach() function. I wasn't aware that Qt classes do not have all
their public functions documented.

Thanks Sean, Scott and Alex.
Greets,


	Ben
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