[Interest] How to properly delete qApp?

[Nikos Chantziaras]

On 16/03/16 14:01, Till Oliver Knoll wrote:
> I don't think you're supposed to delete qApp

Actually you do need to delete it. Most people don't because after 
qApp->exec() returns, the program ends anyway. But if you want to have 0 
leaks, you need to delete your QApplication instance.

Usually you don't delete qApp directly, but just your instance, but 
that's the same thing, really:

   int main(int argc, char** argv)
   {
       QApplication app = new QApplication(/* ... */);
       app->exec();
       delete app;
       // or:
       // delete qApp;
       // which does the same thing.
   }

In normal applications, like the above, deleting it is redundant. You're 
exiting the process, so the environment is going to clean your memory 
anyway. It's still a memory leak, if you're pedantic about it.

If you're using QApplication in a plugin, deleting qApp is actually 
mandatory, otherwise you're leaking the qApp instance when the plugin 
unloads; no one else is going to delete it for you.