Now that we have QStringView::arg(), we can use it to implement a similarly flexible QString::arg(). It's not as straight-forward as in QStringView, though: QString has existing arg() overloads that all become worse matches with the introduction of the new, perfectly-forwarding overload. So in order to allow calling of the other arg() functions, first constrain the new arg() function to arguments that are convertible to QString, QStringView, or QLatin1String, and then delegate to the QStringView version. To stay compatible with the previous overloads, which accepted anything that implicitly converts to QString (in particular, QStringBuilder expressions), add a new overload of qStringLikeToView, taking const QString &. This benefits the existing QStringView and QLatin1View versions, too. [ChangeLog][QtCore][QString] QString::arg(QString, ..., QString) can now be called with more than nine arguments, as well as with QStringViews. Change-Id: I1e717a1bc696346808bcae45dc47762a492c8714 Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org> Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>