<![CDATA[QApplication constructors]]>I'm not sure what is at fault here, but I just noticed that there are some inconsistencies with the QApplication constructors.

If I type the following code in the editor:
@
QCoreApplication *application = new QApplication(
@

the code completion shows me that there are 4 different constructors, but if I press F1 on QApplication, none of the constructors in the help match the signatures of the constructors listed by the code completion.

According to the help:
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QApplication ( int & argc, char ** argv )
QApplication ( int & argc, char ** argv, bool GUIenabled )
QApplication ( int & argc, char ** argv, Type type )
QApplication ( Display * display, Qt::HANDLE visual = 0, Qt::HANDLE colormap = 0 )
QApplication ( Display * display, int & argc, char ** argv, Qt::HANDLE visual = 0, Qt::HANDLE colormap = 0 )
QApplication ( QApplication::QS60MainApplicationFactory factory, int & argc, char ** argv )
@

If I introduce a compile error, the output is:
@
..\Launcher\main.cpp:15: error: no matching function for call to 'QApplication::QApplication(int, int)'
....\QtSDK\Desktop\Qt\4.8.0\mingw\include\QtGui/qapplication.h:389: note: candidates are: QApplication::QApplication(const QApplication&)
....\QtSDK\Desktop\Qt\4.8.0\mingw\include\QtGui/qapplication.h:130: note: QApplication::QApplication(int&, char**, QApplication::Type, int)
....\QtSDK\Desktop\Qt\4.8.0\mingw\include\QtGui/qapplication.h:129: note: QApplication::QApplication(int&, char**, bool, int)
....\QtSDK\Desktop\Qt\4.8.0\mingw\include\QtGui/qapplication.h:128: note: QApplication::QApplication(int&, char**, int)
@

It looks like the code completion at least matches the compiler. The online Qt documentation matches the help in QtCreator. So, is this simply a case of incorrect documentation?

]]>https://forum.qt.io/topic/16182/qapplication-constructorsRSS for NodeMon, 21 Sep 2026 18:17:02 GMTWed, 25 Apr 2012 11:40:52 GMT60<![CDATA[Reply to QApplication constructors on Wed, 25 Apr 2012 15:50:33 GMT]]>I haven't verified this but the last parameter might be marked as internal (it is even named internal if I recall correctly), which means that it is hidden in the documentation (automatically by the documentation tool) but shown in Qt Creator - which just analyzes the source files and suggests what found.

Be aware that some of the constructors are available on certain platforms only.

]]>https://forum.qt.io/post/136918https://forum.qt.io/post/136918Wed, 25 Apr 2012 15:50:33 GMT<![CDATA[Reply to QApplication constructors on Wed, 25 Apr 2012 14:17:28 GMT]]>Yep, noticed that. Which is also interesting since the code
@
QCoreApplication *application = new QApplication(0, 0);
@

Compiles on Ubuntu with the Qt Creator installed from the repository and I think Qt 4.7.1. But it shouldn't...

But that's not the point, the point is the difference between the help file and the actual code.

]]>https://forum.qt.io/post/136905https://forum.qt.io/post/136905Wed, 25 Apr 2012 14:17:28 GMT<![CDATA[Reply to QApplication constructors on Wed, 25 Apr 2012 14:08:53 GMT]]>Note that the first parameter is a reference to int, not an int.

]]>https://forum.qt.io/post/136902https://forum.qt.io/post/136902Wed, 25 Apr 2012 14:08:53 GMT