QGuiApplication - reference in argc argument

  • QGuiApplication have this signature in constructor:
    @QGuiApplication(int & argc, char ** argv)@

    But, why it need? I had derived class from QGuiApplication with signature in constructor without reference:
    @MyApplication(int argc, char ** argv) : QGuiApplication(argc, argv)@

    And of cource, starting at a certain point my app started to fall. I spent many time for fix this problem and now i have a question. Why it need? Integer type have equal or more than twice size than pointer, and using only once. But this reference can create similar errors, as i did.

  • Moderators

    A good question. I've never contemplated that. The only explanation I can think of and that carries enough weight to be mentioned, is that QCoreApplication does reserve right to modify arguments list (see "documentation":http://qt-project.org/doc/qt-4.8/qapplication.html#QApplication - QApplication is what QGuiApplication was before Qt5).
    [quote]Note: argc and argv might be changed as Qt removes command line arguments that it recognizes.[/quote]

  • Ok, i understand. I saw this documentation eirler, but didn't see dependence with argc argument.

  • Moderators

    Theoretically you could check how many arguments Qt has processed by comparing argc value before and after QApplication creation, but honestly this is a little silly use case and I can't find better one.

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