The "flag" is basically "a call to reserve was made"? How do I clear the flag? shrink_to_fit()/squeeze() do this along the way.
-- Best Regards, Andrei ________________________________ From: Ville Voutilainen <ville.voutilai...@gmail.com> Sent: Thursday, September 10, 2020 4:38 PM To: Andrei Golubev <andrei.golu...@qt.io> Cc: development@qt-project.org <development@qt-project.org> Subject: Re: [Development] Important recent changes in QList/QString/QByteArray On Thu, 10 Sep 2020 at 16:04, Andrei Golubev <andrei.golu...@qt.io> wrote: > > Should I expect to do a reserve call with a *smaller* value than my > current size is before removing elements from > a container, in order to set a "target size"? For any standard > container, such a reserve is a complete noop because > it can't be responded to by shrinking a capacity lower than the size, > but with QList it apparently records a preferred size? > > No. If the value passed to reserve is smaller than capacity, we do not > shrink*. > For any passed value, we set a specific flag that the capacity is reserved. > There is no notion of "target size" and "target capacity" is out of scope of > the container (this is something that the user knows about). > Instead, having the flag in place, we can decide whether allocation should > take place or not. When allocation is not obligatory and the capacity > reservation flag is set, we do not reallocate but instead do "something > else": in case of erase - just remove elements, in case of prepend - move > data around (if necessary). > The flag is a mere part of QCC's state. The "flag" is basically "a call to reserve was made"? How do I clear the flag?
_______________________________________________ Development mailing list Development@qt-project.org https://lists.qt-project.org/listinfo/development
