Olivier Goffart wrote: > I would like to add that using a floating point type as a key of a QHash > might be dangerous as there will be == comparison on floating point type, > which might not work well due to rounding issue
The Qwt code is completely uninterested in hashing (or sorting) of doubles. It only uses a simple QList<double> to store doubles for its values. > To my knowledge, Qt never had a qHash function for floating point types. > I just verified it by grepping the diff between Qt 4.5 and Qt 4.6 For Qt <= 4.2 I had to add a dummy implementation of qHash<double> to the Qwt headers. After reporting the bug to the TrollTech support the problem was gone in Qt 4.3. Seems like this ( or a similar ) problem has been reintroduced in Qt 4.6. > To my knowledge, Qt never had a qHash function for floating point types. > I just verified it by grepping the diff between Qt 4.5 and Qt 4.6 I didn't check the QTL code, but I guess the code in qhash.h(875) is not instantiated by the compiler in Qt 4.3 - Qt 4.5 for lists, that are never sorted ? Uwe PS: It seems to be Windows only - I never saw problems with qHash on Linux. _______________________________________________ Qt4-preview-feedback mailing list [email protected] http://lists.trolltech.com/mailman/listinfo/qt4-preview-feedback
