Overloading QDataStream '<<' and '>>' operator help

[Fwomp]

Hello all!

Was hoping somebody could help me with an issue I've run into regarding the overloading of the '>>' and '<<' operators for use with a custom class and QDataStream. I'm trying to create a class and then setup overloaded operators for streaming with a QDataStream, but am getting compilation errors. I've attached a simplified version of the code I'm trying to get working along with the error message below.

Thanks!

main.cpp:

#include "class1.h"
#include <QCoreApplication>
#include <QDataStream>

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

    // No datastream has been setup, this is yet to be implemented.
    QDataStream myStream;
    class1 myClass;

    myClass << myStream;

    return a.exec();
}

class1.cpp:

#include "class1.h"

class1::class1(QObject *parent) : QObject(parent)
{

}

QDataStream & operator>> (QDataStream& stream, class1& image)
{
    stream >> image.myString;
    return stream;
}

QDataStream & operator<< (QDataStream& stream, const class1& image)
{
    stream << image.myString;
    return stream;
}

class1.h

#ifndef CLASS1_H
#define CLASS1_H

#include <QDataStream>
#include <QObject>
#include <QString>

class class1 : public QObject
{
    Q_OBJECT
public:
    explicit class1(QObject *parent = nullptr);

    friend QDataStream & operator>> (QDataStream& stream, class1& image);
    friend QDataStream & operator<< (QDataStream& stream, const class1& image);

private:
    QString myString = "default";
};

#endif // CLASS1_H

error:

main.cpp:13: error: no match for 'operator<<' (operand types are 'class1' and 'QDataStream')
     myClass  << myStream;
              ^

[joeQ]

@Fwomp Hi, friend. Welcome.

Your code's syntax was wrong.

QDataStream myStream;
    class1 myClass;

    ///< myClass << myStream; ///< Its wrong.
   myStream >> myClass; /// stream => myClass,
   myStream << myClass; /// myClass => stream, 

Because, you defined

friend QDataStream & operator>> (QDataStream& stream, class1& image); ///< stream is first arguments, class is second argument
friend QDataStream & operator<< (QDataStream& stream, const class1& image);

if you defined like below:

    friend QDataStream & operator>> (class1& image,QDataStream& stream); ///< first is class and second is stream.
    friend QDataStream & operator<< (const class1& image,QDataStream& stream);

you will right:

class1 >> stream;

[Fwomp]

@joeQ Thanks that's solved it!

[joeQ]

@Fwomp I modified my answer.