[Development] QSharedPointer<QObject> specialization

[Thiago Macieira]

On Friday, 15 June 2018 00:32:13 PDT Philippe wrote:
> QObject has built-in support to a reference count block to support QPointer
> (which is composed of a QWeakPointer)
> 
> When doing QSharedPointer<QObject>, is there a technical reason that
> prevents the QObject control block to be used, rather allocating a new one,
> like it is necessary for common objects?

That's what we did in Qt 4 and that wasn't a good idea. The fact that QPointer 
uses QSharedPointer's control block is an implementation detail, not to be 
relied upon.

Maybe we could save the extra 16 bytes allocation, but the use of both 
QSharedPointer and QPointer isn't likely. And for Qt 6, we may reimplement 
QSharedPointer on top of std::shard_ptr, so this wouldn't be available for 
long as a feature.

> IOW, is a QSharedPointer<QObject> specialization feasible?

To do what?

-- 
Thiago Macieira - thiago.macieira (AT) intel.com
  Software Architect - Intel Open Source Technology Center