I see. But then, if I have QStringView, doesn't that eliminate most of the reasons for needing the other string containing classes? If I want the efficiency of QStringView, won't QString underneath always be the right choice?
In Thiago's example, if I have a QStringView API on my class, would I ever want to switch the QString to a QByteArray? Does using QStringView with QString work as well or better than WByteArray et al? martin ________________________________________ From: development-bounces+martin.smith=theqtcompany....@qt-project.org <development-bounces+martin.smith=theqtcompany....@qt-project.org> on behalf of Marc Mutz <marc.m...@kdab.com> Sent: Monday, October 19, 2015 11:26 PM To: development@qt-project.org Subject: Re: [Development] RFC: Proposal for a semi-radical change in Qt APIs taking strings On Monday 19 October 2015 21:56:54 Smith Martin wrote: > >This API here simply cannot exist because the returned value would be a > >dangling reference. > > I don't understand. Implicit for using the QStringView data() function is > knowing that once the QByteArray is set, it is never changed. Then the > data() function is ok, isn't it? A QStringView points to QChar* (or ushort*) while a QByteArray only provides char*. The fromLatin1() (say) call thus necessary will create a temporary QString, which will bind to the returned QStringView, but will already be destroyed (taking the data QStringView references with it) when control returns to the caller. This particular mistake is easy to prevent statically, though: QStringView(QString &&) = delete; 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 _______________________________________________ Development mailing list Development@qt-project.org http://lists.qt-project.org/mailman/listinfo/development
