How to Program C++11 Using Qt5?

Question

I'm getting ready to program a cross-platform project with my friend. We decided on using Qt and gcc as our IDE and toolchain respectively. He works on Linux, I work on Windows.

However, gcc on Linux isn't necessarily gcc on Windows. More specifically, Qt on Windows installs mingw with gcc 4.4 and my friend has gcc 4.7. So I tried getting a more recent gcc version for windows.

My current version of Qt is 5 and using gcc 4.7 downloaded and installed from this site: http://www.equation.com/servlet/equation.cmd?fa=fortran

I installed it in C:\QtSDK\mingw and simply overrode all the files existing from the Qt installation. I figured that I wouldn't have to reconfigure anything in Qt if I just took the short route.

However, even using the compiler flags:

QMAKE_CXXFLAGS += -std=c++0x (Qt 4.7)

and

CONFIG   += c++11 (Qt5)

the IDE or toolchain fails to compile a simple range-based for loop:

int main(int argc, char *argv[])
{
    int my_array[5] = {1, 2, 3, 4, 5};
    for (auto x : my_array)
        std::cout << x << std::endl;

    return 0;
}

or initializer-lists:

int main(int argc, char *argv[])
{
    QVector<int> testsData { 1, 2, 10, 42, 50, 123  };
    QStringList options = { QLatin1String("foo"), QLatin1String("bar")  };

    return 0;
}

However, looking at the implementation details of gcc 4.7, both of these features- and more- should be readily available.

Has anyone else tried to use gcc and Qt for Windows? If so, how did you get it to work? I would like a solution using gcc 4.6 or 4.7, but will settle for less if it is not at all possible.

Alternatively, is there a dev environment for Linux and Windows that makes use of C++11 features? I would also settle for something besides Qt if it just works...

I used the sources:

C++0x in Qt (Qt 4.7-4.8)

C++11 in Qt5

Answer 1

QMAKE_CXXFLAGS += -std=c++0x

Results in an error because you're not using the MinGW compiler. "D9002: Ignoring unknown option -std=c++0x" is an error from the MSVC compiler.

In QtCreator, go to the projects tab(on the left) and change the toolchain you're using. If it hasn't auto-detected MinGW, you're going to have to add it yourself by clicking on the manage button.