Re: Fw: Fwd: [Qt bugreports] Updates for QTBUG-75585: Massive performance regression in QML Date object

Am Freitag, 25. September 2020, 02:55:52 CEST schrieb Robert Krawitz:
> > One question about this: I assume that we read every datetime at least
> > once
> > and rarely alter a datetime. Why then do the whole dance with the mutable
> > qint64? We could just as well initialize the qint64 on construction and on
> > every modification...
> 
> The only thing is that we do need to know whether a QDateTime is invalid;
> there is specifically defined behavior in that case.  So we do need that
> reserved number for that purpose.

Whether QDateTime::isValid fits the bill or the magic number is the better 
solution doesn'T matter to me too much - I just wanted to avoid the mutable 
member variable if possible.

Cheers,
  Johannes