Suggests to use QLatin1String("") instead of QStringLiteral() and QStringLiteral("").
QStringLiteral should only be used where it would reduce memory allocations.
Note that, counterintuitively, both QStringLiteral().isNull() and QStringLiteral("").isNull() are false,
so do use exactly QLatin1String("") and not QLatin1String(), in both cases.
If in your code isNull() and isEmpty() are interchangeable, then simply use QString().