QFile Problem

LainOnTheWired

I try to write a file with the QFile library with the following code like it is in the QT documentation..

QFile file("out.txt");
    if (!file.open(QIODevice::WriteOnly | QIODevice::Text))
        return;

    QTextStream out(&file);
    out << "The magic number is: " << 49 << "\n";

But it complains about the file.open part.

J.Hilk

@LainOnTheWired said in QFile Problem:

But it complains about the file.open part.

you need to be more specific

LainOnTheWired

It says canditate function not vaible: no knowen conversation from int to OpenMode(aka QFlags<QIODevice OpenModeFlag>) for 1st argument. Is this enough or do you need more ?

J.Hilk

@LainOnTheWired
did you include QFile ?

#include <QFile>

LainOnTheWired

Yes it is included.

VRonin

very strange... in any case you can replace

if (!file.open(QIODevice::WriteOnly | QIODevice::Text))
        return;

with

if (!file.open(QIODevice::WriteOnly))
        return;
file.setTextModeEnabled(true);

JonB

@VRonin
I'd be worried if I got his error message! I don't do C++/includes, but does he need to also #include <QIODevice> for the flag definitions?

LainOnTheWired

Yes thats it with include<QIODevice> it works thanks so much :) and you need to include #include <qtextstream.h> for the stream too.

JKSH

@LainOnTheWired said in QFile Problem:

Yes thats it with include<QIODevice> it works thanks so much :) and you need to include #include <qtextstream.h> for the stream too.

That's very odd. The QFile header should already contain #include <QIODevice>...

Has the QFile header been modified?

VRonin

@JonB said in QFile Problem:

I'd be worried if I got his error message!

I wouldn't. It just cannot find the operator|() that is defined as part of specialising QFlags. Not a big deal

JonB

@VRonin
That's precisely what I meant! Perhaps "worried" was too strong a word :) The error message suggested to me that the QFlags were not working correctly with the | operator, hence my guess about not having the correct #include. I intended to suggest that the OP should pursue why this appeared to be the case.

LainOnTheWired

It is the fault of KDevelop, if i have only the QFile include it puts this error message but if i compile the program it works correctly. The error message is wrong. Very strange and no i have not modified the header file.

JonB

@LainOnTheWired

The error message is wrong.

Up to you, but the compiler error/warning message cannot be "wrong". If it warns it means what it says in terms of not having the definition, compilers don't invent error messages. It may work at runtime if it's only a warning and the semantics actually allow an int operator|() to work in this case, which it probably does.

Likely perhaps: if you have other #includes (e.g. from "KDevelop") prior (or possibly post) to your #include <QFile> that might affect definitions/behaviour and cause your issue....

jsulm

@JonB I think the error is not coming from the compiler but from the Clang Code Model which is known for producing many false positives.
@LainOnTheWired You can try to disable Clang Code Model

JonB

@jsulm
Ohhh, I don't know anything about CLang or that the OP is using that, apologies then if my comment was misleading.

jsulm

@JonB No problem! Actually the OP was not clear when saying "it puts this error message" - this can be the compiler or the code model.