Size policies can be compared for equality,
so qHash should be overloaded, too.
[ChangeLog][QtWidgets][QSizePolicy] Added qHash(QSizePolicy).
Change-Id: Id219f47ac6cb236efdd73cad7b892c8efd034d5c
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@theqtcompany.com>
Reviewed-by: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>