[Development] QUIP 6: removing top-level const from return types

[Ville Voutilainen]

On 23 May 2017 at 12:00, Marc Mutz <marc.mutz at kdab.com> wrote:
>> Maybe, but I have some questions: the review for removing top-level consts
>> from QRegion says "It has no effect and inhibits move semantics." How does
>> it inhibit move semantics? How is this even a SiC? What _positive_ impact
>> do these changes have?
>
> See Olivier's example:
>
>    QPixmap pix;
>    pix = splash.pixmap();
>
> with
>
>    const QPixmap pixmap() const;
>
> calls the copy assignment operator, while with
>
>    QPixmap pixmap() const;
>
> it calls, as expected, the _move_ assignment operator.

Ok, yeah, I was using constructors, not assignment operators so I
failed to see the
issue.

So, we are doing this to improve performance of otherwise valid code,
but not making this
change doesn't make anything worse, right?