GCC problem with QHash as optionnal parameter in function

[nooky59]

Hello,

I usually compile my code with the MSVC compiler but I tried yesterday to compile it on Mac OS X with GCC.

I have a function declared like that :

void myfunction(const QHash<QString, QVariant> &callback = QHash<QString, QVariant>());

void myfunction(const QHash<QString, QVariant> &callback = QHash<QString, QVariant>());

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It compiles well in MSVC but it seems GCC as some troubles with such a construct.

I have changed my code to take a pointer :

void myfunction(const QHash<QString, QVariant> *callback = 0);

void myfunction(const QHash<QString, QVariant> *callback = 0);

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But is there a way to keep a construct without pointer which accept such an optionnal parameter with a template class ?

[wysota]

Try typedeffing the hash.

[somekool]

I am having the same problem, compiling akonadi 1.7.1 with Qt 4.8.0 under Snow Leopard.
I know this thread is 4 years old, that's make me even more surprise.

thank you for the suggestion, typedeffing it worked.

but couldn't this be fixed?

it feels weird to me to fill a "bug" report to akonadi about it ... but anyway..

thanks

[ChrisW67]

What version of GCC and what is the error message?

My GCC 4.5.3, Qt 4.7.4 on Linux produces no error or warning on this:

#include <QtCore>
#include <QDebug>
 
void myfunction(const QHash<QString, QVariant> &callback = QHash<QString, QVariant>())
{
    qDebug() << callback.keys();
}
 
int main(int argc, char *argv[])
{
    QCoreApplication app(argc, argv);
 
    myfunction();
 
    QHash<QString, QVariant> h;
    h.insert("A", QVariant(1));
    h.insert("B", QVariant(1));
    myfunction(h);
 
    return 0;
}

#include <QtCore>
#include <QDebug>

void myfunction(const QHash<QString, QVariant> &callback = QHash<QString, QVariant>())
{
    qDebug() << callback.keys();
}

int main(int argc, char *argv[])
{
    QCoreApplication app(argc, argv);

    myfunction();

    QHash<QString, QVariant> h;
    h.insert("A", QVariant(1));
    h.insert("B", QVariant(1));
    myfunction(h);

    return 0;
}

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