2012/1/15 Gábor Lehel <illiss...@gmail.com>: > 2012/1/7 Thiago Macieira <thiago.macie...@intel.com>: >> On Saturday, 7 de January de 2012 01.03.50, David Faure wrote: >>> Shouldn't we clean that up for Qt5 and just use a bool for the contains >>> method again? The Qt4 API ensures that nobody still has if (contains()==2) >>> in their code anyway. >> >> I think it should be gone. >> >> For the few methods where a boolean is needed and arithmetic is wrong, the >> suggestion is to use the RestrictedBool solution: >> >> typedef int ClassName:: *RestrictedBool; > > Apologies for the off-topic: > > Is the RestrictedBool technique documented anywhere? What it does, how > it works, why it works? I can see that it's using a member pointer to > simulate a bool (presumably to avoid implicit casts to int and such), > but not why this is preferable to a void* (fewer operations > permitted?), and in particular why it has to be a pointer to a member > of the specific class it is being used for instead of some > globally-defined dummy class (even fewer operations permitted? but > which ones?). Googling found nothing except the existing usage in > QSharedPointer.
See f.i. http://www.artima.com/cppsource/safebool.html Cheers, -- Giuseppe D'Angelo _______________________________________________ Development mailing list Development@qt-project.org http://lists.qt-project.org/mailman/listinfo/development
