I'm trying to get information for updating the documentation for QList. At the moment, it is misleading, judging by what you are saying. Maintaining the documentation isn't a red herring. It's actually my job.
martin ________________________________________ From: [email protected] <[email protected]> on behalf of Marc Mutz <[email protected]> Sent: Sunday, July 12, 2015 2:03 AM To: [email protected] Subject: Re: [Development] HEADS UP: Don't use QList, use Q_DECLARE_TYPEINFO On Saturday 11 July 2015 21:50:05 Smith Martin wrote: > Suppose (as in the use case that started this thread) that your > QList/QVector/QLinkedList will only have a small number of elements in it. > Almost always less than 5. Never more than about 8. Does this change the > analysis at all? In particular, does it minimize the performance > differences? > > And suppose the use case also assumes that you add all the elements to the > container immediately and then you process the container sequentially > immediately after that. So there is no inserting, no searching, and no > other mallocs. If you have only a very small number of elements, you should either be using a QVarLengthArray to avoid _any_ container-related heap allocations, or else a std::vector, because the overhead of the d-pointer is relatively-speaking a lot higher at small element counts. And please stop chasing red herrings. It was _not_ the use of QList<ParsedSomething> in qdoc that originated this thread. Look at my Gerrit list of changes, merged and open. And my blog post is five years old. Thanks, Marc -- Marc Mutz <[email protected]> | Senior Software Engineer KDAB (Deutschland) GmbH & Co.KG, a KDAB Group Company Tel: +49-30-521325470 KDAB - The Qt Experts _______________________________________________ Development mailing list [email protected] http://lists.qt-project.org/mailman/listinfo/development _______________________________________________ Development mailing list [email protected] http://lists.qt-project.org/mailman/listinfo/development
