Invalid conversion in a simple 'hello world' zero widget cmake project on app.exec();

TheTobruk

Hi,

I hope I posted on the right subforum.
I created a very, very simple project without any widgets in the QApplication object and tried to run it.
The code:

#include <QApplication>

int main(int argc, char* argv[]) {
    QApplication qapp(argc, argv);
    return qapp.exec;
}

cmake .pro:

QT += core gui
greaterThan(QT_MAJOR_VERSION, 4) : QT += widgets
SOURCES += \
    sause.cpp

I get the following error on compile-time:

sause.cpp:5: error: invalid conversion from 'int (*)()' to 'int' [-fpermissive]
     return qapp.exec;
                 ^

I think the code is fine, because argv should point to the first element in the array of argv[], no problem there. To be sure though, I tried converting argv into a memory path (&argv), but that didn't work.

Anything I could try? Is this an installation problem? Missing kits, bad compiler?
my kit and compiler

Chris Kawa

Hi, welcome to the forum.
The error says it: error: invalid conversion from 'int (*)()' to 'int' which means you're trying to convert a function pointer to an int.

Change

return qapp.exec; //taking an address of a function

to

return qapp.exec(); //calling a function

and you'll be good to go.

TheTobruk

I am so dumb :D

Important: Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

Invalid conversion in a simple 'hello world' zero widget cmake project on app.exec();