On Saturday 17 October 2015 01:52:27 Kurt Pattyn wrote: > > Bottomline: I don't need a fancy anylysis to tell me that less > > allocations = faster programs = more happy Qt users. > > But to what extent? If I run my application on a workstation, the effect is > negligible, as my application has more to do than handling strings. If I > have an embedded application, every piece of performance gain could > benefit, but my experience tells me (for MY use cases) that the graphics > stack is more a bottleneck than string handling.
I object to the notion that a desktop would not benefit from more efficient string handling. Hardware doesn't get faster the way it used to. If the speed of C++ wasn't needed, your workstation would only run Java apps (and Sun tried, but failed). > > > > And please don't forget that QString fanboys can continue to massacre the > > heap if they so wish. After all, we've had QStringRef for a long time > > now, but most people still write str.mid(n).toInt() instead of > > str.midRef().toInt(). QStringView won't change that: A function taking > > QStringView accepts a QString, too (either by implicit conversion, or > > where it makes sence, by QString overload). > > The word 'fanboys' disturbs me (I know you don't mean it that way) because > there are no 'hard' numbers on how 'bad' the current situation really is. > It would really be helpful to have an idea how 'real-world' applications > suffer from the current implementation of QString. That would give a very > good context to decide how Qt can help to leverage these problems. If you want real-world numbers, follow the optimisations Milian did in moc. IIRC, he documented the speedup.They are not (all) string-related, but I also don't claim that QStringView will single-handedly make your apps go faster. I wrote about QList already. There's more where these topics came from, but essentially they all boil down to: "minimise allocations". > That said, I like the idea of QStringView. Thanks, Marc -- Marc Mutz <marc.m...@kdab.com> | Senior Software Engineer KDAB (Deutschland) GmbH & Co.KG, a KDAB Group Company Tel: +49-30-521325470 KDAB - The Qt Experts _______________________________________________ Development mailing list Development@qt-project.org http://lists.qt-project.org/mailman/listinfo/development
