Yes, qgraphicsitem_cast isn't as powerful as dynamic_cast, but this simplicity also makes it faster.
Anyway, Jonathan asked about casting C++ objects and now has several methods to choose from. :-) On May 23, 2013 9:17 PM, "Jan Kundrát" <j...@flaska.net> wrote: > On Thursday, 23 May 2013 19:04:53 CEST, Constantin Makshin wrote: > > There's also qgraphicsitem_cast made specifically for casting to classes > > derived from QGraphicsItem. > > It is also of very limited value in real world because it does not support > inheritance -- it can only cast to the exact type of the item in question. > > Suppose you have a hierarchy -- C derives from B which derives from A. A > dynamic_cast of a C to all of B and A will succeed, but a > qgraphicsitem_cast will return a null pointer when casting a C* into either > B* or C*, only succeeding when casting to A*. Depending on what you're > looking for, being able to fully utilize the inheritance tree might or > might not be important for you. > > (Actually, the bits above are a little bit simplified; the casting is > performed based on the target class' Type member, so in cases where you > e.g. derive from a QGraphicsItemText but forget to provide your own Type > value, a cast to QGraphicsItemText will succeed. Of course, you cannot > distinguish between a QGraphicsItemText and your own class via > qgraphicsitem_cast in this situation.) > > Cheers, > Jan > > -- > Trojitá, a fast Qt IMAP e-mail client -- http://trojita.flaska.net/ > _______________________________________________ > Interest mailing list > Interest@qt-project.org > http://lists.qt-project.org/mailman/listinfo/interest >
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