[Development] Making QScopedPointer scoped (again)

[Stephen Kelly]

Hi there,

Commit 5b9006bbdba7dcab01b8e640554a7d7a4b64f76b in qtbase added move 
capability to QScopedPointer. 

That means that in Qt 5.2, if you use C++11, you can do this:

 int main(int argc, char **argv)
 {
   QScopedPointer<int> p_out;
   {
     QScopedPointer<int> p(new int);
     p_out = std::move(p);
   }
 }

However, if you want to move a QScopedPointer like that, then you don't want a 
QScopedPointer at all, but a std::unique_ptr instead.

It also means that you can put a QScopedPointer in your API:

 QScopedPointer<int> returnScopedPointer()
 {
   QScopedPointer<int> p(new int);
   return p;
 }

 int main(int argc, char **argv)
 { 
   QScopedPointer<int> p = returnScopedPointer();
 }


Again, this is what std::unique_ptr is for. We should not try to turn 
QScopedPointer into an attempt at a NIH std::unique_ptr. Where people have a 
need for a std::unique_ptr, they should use it. We should not adapt 
QScopedPointer to fit the need instead.

Adding a move contructor to QScopedPointer makes no sense, because moving
means 'escaping the scope', which breaks the fundamental point of
QScopedPointer. QScopedPointer is different to std::unique_ptr and should 
remain so.

Please approve:

 https://codereview.qt-project.org/#change,64428

Thanks,

-- 
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Stephen Kelly <stephen.kelly at kdab.com> | Software Engineer
KDAB (Deutschland) GmbH & Co.KG, a KDAB Group Company
www.kdab.com || Germany +49-30-521325470 || Sweden (HQ) +46-563-540090
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