[Development] std::allocate_shared for QSharedPointer

[Thiago Macieira]

On Saturday, 9 September 2017 05:46:49 -03 Sean Harmer wrote:
> Does anybody have any plans to add such a facility? Or is there some
> other facility to avoid operator new here for both the QSP and the
> object itself?

There are no plans. We don't have allocators anywhere in Qt, so I doubt this 
will ever happen.

> The QSharedPointers are used in the public API as we can't use
> std::shared_ptr there. I guess the closest I can get without such a
> facility is to maintain a pool of QSharedPointers, a pool of the objects
> and use QSharedPointer::reset() when recycling or just keep the two pools
> in sync whcih I guess makes sense anyway.

That won't help:

    inline void reset(T *t)
    { QSharedPointer copy(t); swap(copy); }

Have you benchmarked and found out that the malloc() for the 
QtSharedPointer::ExternalRefCountData pointer is the culprit?

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