[Development] Making QScopedPointer scoped (again)

[Peter Kümmel]

On 04.09.2013 07:36, Olivier Goffart wrote:
> On Tuesday 03 September 2013 21:20:20 Peter Kümmel wrote:
>> It is of great benefit that you never had to think about if
>> QScopedPointer(5.1) will delete when leaving scope.
>
> That's not true.
>
>   QScopedPointer<...> myPtr(foo());
>   myPtr.take();

Sure, but then you don't pass a QScopedPointer and have to care about the plain pointer.

>
> And it does not delete when leaving the scope.
>
> Think of qMove(myPtr) of a safer convenience to the already existing take()
>
>> The main point is that in Qt is nothing like std::unique_ptr,
>
> False again.

only when QScopedPointer is movable


  QScopedPointer is almost exactly the same as unique_ptr. They
> have the same API.

> Compare http://en.cppreference.com/w/cpp/memory/unique_ptr and http://qt-project.org/doc/qt-5.0/qtcore/qscopedpointer.html and tell me again they are
> nothing like eachother.

The point of the thread is not functionality but naming.

>
> The documentation of unique_ptr even starts with: "std::unique_ptr is a smart
> pointer that retains sole ownership of an object through a pointer and
> destroys that object when the unique_ptr goes out of scope."
>
> It is unfortunate that the standard did not choose the name
> std::scoped_pointer,  but that's not the first time the standard and Qt are
> using different name (QByteArray <> std::string, QLinkedList <> std::list, ...)
>
> (I assume you meant s/Qt/QScopedPointer/)
>
>> so when it is needed and we can't use std::unique_ptr, we have to introduce
>> a QUniquePointer. This is better than to add features to classes which are
>> contradictorily to their naming.
>
> Based on all the false assumptions in your mail, I think it's safe to discard
> your conclusion.
>

Maybe boost is also some sort of reference; there the scoped pointer is also not movable:
http://www.boost.org/doc/libs/1_54_0/libs/smart_ptr/scoped_ptr.htm


With making QScopedPointer movable we cemented the bad naming.

Peter