Qt 5.15 has QVariant compare operators deprecated:
#if QT_DEPRECATED_SINCE(5, 15)
QT_DEPRECATED inline bool operator<(const QVariant &v) const
{ return compare(v) < 0; }
QT_DEPRECATED inline bool operator<=(const QVariant &v) const
{ return compare(v) <= 0; }
QT_DEPRECATED inline bool operator>(const QVariant &v) const
{ return compare(v) > 0; }
QT_DEPRECATED inline bool operator>=(const QVariant &v) const
{ return compare(v) >= 0; }
#endif
There is the protected compare function, as seen used above:
int compare(const QVariant &other) const;
But, as said, it is protected.
How to compare QVariant values in Qt 5.15 when using QT_DEPRECATED_SINCE(5, 15), with the same (arguably broken) semantics that were used before?
Unfortunately it seems we are supposed to ignore the deprecation warning. Qt6 introduced QVariant::compare but there is no equivalent in Qt5.15
Some solutions were discussed on Qt dev mailing list but the corresponding patch got stale AFAIK