cannot convert ‘const QString’ to ‘const QLocale&’

xavierbaez

Hello. This error is affecting building an application and it’s affecting other files in the stacktrace. Have anybody experienced a similar problem? Hopefully with QStringnand QLocale&

I’m upgrading an application from Qt5 to Qt6.

Thanks

Christian Ehrlicher

@xavierbaez Please re-read your question and ask yourself how we should help here.

Provide some code where you've problems with.

xavierbaez

@Christian-Ehrlicher I think I asked the question correctly

jsulm

@xavierbaez Really?!
You do not even show the code which is causing this error - how should anybody help you?!

Chris Kawa

@xavierbaez The error message says exactly what's wrong - you're passing a QString to where a QLocale is expected. Yes, a lot of people experience this problem with different types. The fix is always the same. Provide an argument of type that is expected.
As Christian said - we can't tell you anything else without you showing the code that exhibits this error.

xavierbaez

@Chris-Kawa okay thanks maybe I forgot to mention this worked and compiled and built fine with Qt5, so I guess the question 🙋🏻‍♂️ is more with “why would it work on Qt5 and not in Qt6”

Christian Ehrlicher

@xavierbaez Again: provide some code where it happens!

JonB

@xavierbaez said in cannot convert ‘const QString’ to ‘const QLocale&’:

“why would it work on Qt5 and not in Qt6”

Maybe because a function which took a QString in Qt5 was changed to require a QLocale& in Qt6?

jsulm

@xavierbaez said in cannot convert ‘const QString’ to ‘const QLocale&’:

why would it work on Qt5 and not in Qt6

Because there were changes between Qt5 and Qt6, but as long as you refuse to show the code causing this error we can only guess...

xavierbaez

@jsulm here’s the code


bool BasicLogger::match(QString logFileName) const

jsulm

@xavierbaez said in cannot convert ‘const QString’ to ‘const QLocale&’:

here’s the code

No, this is not the code causing that error...

JonB

@xavierbaez
Nobody can answer from this without knowing what class BasicLogger is, since it's not a supplied Qt class, and hence the definition of match() if you are overriding it (or perhaps some other context)? You are amazingly "economical" with what you show in order to answer your question, I cannot understand why. In itself there is nothing you show which would error requiring QLocale instead of the QString you specify.

xavierbaez

@JonB

bool BasicLogger::match(QString logFileName) const
{
    QRegExp re(QString(matchPattern).arg(_params.fileName));
    return re.exactMatch(logFileName);
}

Christian Ehrlicher

@xavierbaez said in cannot convert ‘const QString’ to ‘const QLocale&’:

QRegExp

This was deprecated in Qt5 and removed in Qt6 so I would be surprised if this compiles at all.

xavierbaez

@Christian-Ehrlicher said in cannot convert ‘const QString’ to ‘const QLocale&’:

@xavierbaez said in cannot convert ‘const QString’ to ‘const QLocale&’:

QRegExp

This was deprecated in Qt5 and removed in Qt6 so I would be surprised if this compiles at all.

Would you be so kind to let me know how would you write this?

JonB

@xavierbaez said in cannot convert ‘const QString’ to ‘const QLocale&’:

QRegExp re(QString(matchPattern).arg(_params.fileName));
return re.exactMatch(logFileName);

Try (untested)

QRegularExpression re(QRegularExpression::anchoredPattern(QString(matchPattern).arg(_params.fileName)));
return re.match(logFileName).hasMatch();

You will need to change #include <QRegExp> to #include <QRegularExpression>.

Volker75

Hallo,

i got the same problem converting from Qt 5 to Qt 6. I understand the problem, but i don't know how to fix it.
In my source it is this:

app.installTranslator(&TTranslator);                    //this is fine
QLocale::setDefault(TSettings->language);     //this is wrong

While TSettings->language is a QString reading from QSettings.

Chris Kawa

@Volker75 QLocale(const QString&) constructor was marked explicit in Qt6, so you have to, well, be explicit when you use that constructor :)

QLocale::setDefault(QLocale(TSettings->language));

Volker75

@Chris-Kawa said in cannot convert ‘const QString’ to ‘const QLocale&’:

QLocale(

ah... so easy.. Thank you very much! I just tried and it can compile now that file. (Not the whole project yet, there are more errors, but i hope i can fix them myself)

xavierbaez

@JonB said in cannot convert ‘const QString’ to ‘const QLocale&’:

@xavierbaez said in cannot convert ‘const QString’ to ‘const QLocale&’:
QRegExp re(QString(matchPattern).arg(_params.fileName));
return re.exactMatch(logFileName);
Try (untested)
QRegularExpression re(QRegularExpression::anchoredPattern(QString(matchPattern).arg(_params.fileName)));
return re.match(logFileName).hasMatch();
You will need to change #include <QRegExp> to #include <QRegularExpression>.

Yeah that worked thank you so much.