Glimpse in kdereview
Aaron J. Seigo
aseigo at kde.org
Sun Mar 30 22:33:00 BST 2008
On Sunday 30 March 2008, Kåre Särs wrote:
> On Sunday 30 March 2008 23:59:40 Aaron J. Seigo wrote:
> > suggestion: return a QImage instead of taking one by reference, and set
> > it to QImage() on failure. the return can easily check for img.isNull()
> > .. makes for a slightly more natural feeling API?
>
> I made it a reference to save one copy operation. if you have a big image
> it could be significant.
from the QImage docs:
"QImage objects can be passed around by value since the QImage class uses
implicit data sharing."
in this case the QImage is created in the method, then passed back by
reference to the QImage object in the consumer at which point the QImage in
makeQImage is destroyed (no further modifications) ... so no data is actually
copied, just pointers moved around in the dtprs. quite fast, no matter what
size the image actually is =)
--
Aaron J. Seigo
humru othro a kohnu se
GPG Fingerprint: 8B8B 2209 0C6F 7C47 B1EA EE75 D6B7 2EB1 A7F1 DB43
KDE core developer sponsored by Trolltech
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 194 bytes
Desc: This is a digitally signed message part.
URL: <http://mail.kde.org/pipermail/kde-core-devel/attachments/20080330/4902dbc2/attachment.sig>
More information about the kde-core-devel
mailing list