Qt Serialization no match for operator << operand types are 'QDataStream'

I have a problem during serialization with a simple Managed Structure.

My Class Header

class MappySaver

{



public:

    MappySaver();



    //structure

    struct Tile

    {

    public:

        int ID;

        int x,y,w,h;

        QRect rect;

    };



    QList<Tile> Tiles;

    QObject t;

    Tile tile;



};



QDataStream& operator << (QDataStream& s, const MappySaver::Tile& tile);

QDataStream& operator >> (QDataStream& s, MappySaver::Tile& tile);





#endif // MAPPYSAVER_H

and source cpp

   QDataStream &operator<<(QDataStream &s, const MappySaver::Tile& tile)

{

    s << tile;

    return s;

}

When I try to compile this, I get this error:

error: no match for 'operator<<' (operand types are 'QDataStream' and 'const MappySaver::Tile')

template <typename T> //QDataStream.h

QDataStream& operator<<(QDataStream& s, const QList<T>& l)

{

    s << quint32(l.size());

    for (int i = 0; i < l.size(); ++i)

        s << l.at(i);

    return s;

}

I use this class to serialize a list.
On the main form, I have a widget with the same data.

And I use this method for try to serialize.

QString filename = QFileDialog::getSaveFileName(this,

                                                tr("Seleziona il file da salvare"),"",

                                            tr("File Mappa (*.mp2d)"));



MappySaver::Tile t;

    MappySaver m;





    for(int i = 0; i < ui->maps->Tiles.count(); i++)

    {

        t.ID = ui->maps->Tiles[i].ID;

        t.h = ui->maps->Tiles[i].h;

        t.rect = ui->maps->Tiles[i].rect;

        t.w = ui->maps->Tiles[i].w;

        t.x = ui->maps->Tiles[i].x;

        t.y = ui->maps->Tiles[i].y;



        m.Tiles.append(t);

    }







        QFile f(filename);



         if(!f.open(QIODevice::WriteOnly))

         {



         }else

         {

             QDataStream out(&f);

             out.setVersion(QDataStream::Qt_4_8);



             out << m.Tiles;



         }



        f.flush();

        f.close();

How can I fix this problem and serialize?

edited Nov 23 '18 at 14:29

asked Nov 23 '18 at 10:49

giovanni mannuoio

At first glance the compiler tells you what's wrong. You wrote functions for MappySaver but pass MappySaver::Tile as argument.

– vahancho
Nov 23 '18 at 10:59

just create the function QDataStream& operator << (QDataStream& s, const MappySever::Tile& tile);

– Alexander Chernin
Nov 23 '18 at 11:48

@AlexanderChernin i have an error Segmentation Fault.

– giovanni mannuoio
Nov 23 '18 at 14:09

1

Yep, you're getting recursion there. The function is calling itself. More appropriately, you might be wanting to output individual << tile.ID, tile.x, etc?

– TrebuchetMS
Nov 23 '18 at 14:43

1

@TrebuchetMS Yea! Work! Tanks a lot Trebuchet. i have changend whit your example and work! image.ibb.co/f0FB5V/Immagine.png

– giovanni mannuoio
Nov 23 '18 at 15:09

|
show 4 more comments

I have a problem during serialization with a simple Managed Structure.

My Class Header

class MappySaver

{



public:

    MappySaver();



    //structure

    struct Tile

    {

    public:

        int ID;

        int x,y,w,h;

        QRect rect;

    };



    QList<Tile> Tiles;

    QObject t;

    Tile tile;



};



QDataStream& operator << (QDataStream& s, const MappySaver::Tile& tile);

QDataStream& operator >> (QDataStream& s, MappySaver::Tile& tile);





#endif // MAPPYSAVER_H

and source cpp

   QDataStream &operator<<(QDataStream &s, const MappySaver::Tile& tile)

{

    s << tile;

    return s;

}

When I try to compile this, I get this error:

error: no match for 'operator<<' (operand types are 'QDataStream' and 'const MappySaver::Tile')

template <typename T> //QDataStream.h

QDataStream& operator<<(QDataStream& s, const QList<T>& l)

{

    s << quint32(l.size());

    for (int i = 0; i < l.size(); ++i)

        s << l.at(i);

    return s;

}

I use this class to serialize a list.
On the main form, I have a widget with the same data.

And I use this method for try to serialize.

QString filename = QFileDialog::getSaveFileName(this,

                                                tr("Seleziona il file da salvare"),"",

                                            tr("File Mappa (*.mp2d)"));



MappySaver::Tile t;

    MappySaver m;





    for(int i = 0; i < ui->maps->Tiles.count(); i++)

    {

        t.ID = ui->maps->Tiles[i].ID;

        t.h = ui->maps->Tiles[i].h;

        t.rect = ui->maps->Tiles[i].rect;

        t.w = ui->maps->Tiles[i].w;

        t.x = ui->maps->Tiles[i].x;

        t.y = ui->maps->Tiles[i].y;



        m.Tiles.append(t);

    }







        QFile f(filename);



         if(!f.open(QIODevice::WriteOnly))

         {



         }else

         {

             QDataStream out(&f);

             out.setVersion(QDataStream::Qt_4_8);



             out << m.Tiles;



         }



        f.flush();

        f.close();

How can I fix this problem and serialize?

edited Nov 23 '18 at 14:29

asked Nov 23 '18 at 10:49

giovanni mannuoio

At first glance the compiler tells you what's wrong. You wrote functions for MappySaver but pass MappySaver::Tile as argument.

– vahancho
Nov 23 '18 at 10:59

just create the function QDataStream& operator << (QDataStream& s, const MappySever::Tile& tile);

– Alexander Chernin
Nov 23 '18 at 11:48

@AlexanderChernin i have an error Segmentation Fault.

– giovanni mannuoio
Nov 23 '18 at 14:09

1

Yep, you're getting recursion there. The function is calling itself. More appropriately, you might be wanting to output individual << tile.ID, tile.x, etc?

– TrebuchetMS
Nov 23 '18 at 14:43

1

@TrebuchetMS Yea! Work! Tanks a lot Trebuchet. i have changend whit your example and work! image.ibb.co/f0FB5V/Immagine.png

– giovanni mannuoio
Nov 23 '18 at 15:09

|
show 4 more comments

I have a problem during serialization with a simple Managed Structure.

My Class Header

class MappySaver

{



public:

    MappySaver();



    //structure

    struct Tile

    {

    public:

        int ID;

        int x,y,w,h;

        QRect rect;

    };



    QList<Tile> Tiles;

    QObject t;

    Tile tile;



};



QDataStream& operator << (QDataStream& s, const MappySaver::Tile& tile);

QDataStream& operator >> (QDataStream& s, MappySaver::Tile& tile);





#endif // MAPPYSAVER_H

and source cpp

   QDataStream &operator<<(QDataStream &s, const MappySaver::Tile& tile)

{

    s << tile;

    return s;

}

When I try to compile this, I get this error:

error: no match for 'operator<<' (operand types are 'QDataStream' and 'const MappySaver::Tile')

template <typename T> //QDataStream.h

QDataStream& operator<<(QDataStream& s, const QList<T>& l)

{

    s << quint32(l.size());

    for (int i = 0; i < l.size(); ++i)

        s << l.at(i);

    return s;

}

I use this class to serialize a list.
On the main form, I have a widget with the same data.

And I use this method for try to serialize.

QString filename = QFileDialog::getSaveFileName(this,

                                                tr("Seleziona il file da salvare"),"",

                                            tr("File Mappa (*.mp2d)"));



MappySaver::Tile t;

    MappySaver m;





    for(int i = 0; i < ui->maps->Tiles.count(); i++)

    {

        t.ID = ui->maps->Tiles[i].ID;

        t.h = ui->maps->Tiles[i].h;

        t.rect = ui->maps->Tiles[i].rect;

        t.w = ui->maps->Tiles[i].w;

        t.x = ui->maps->Tiles[i].x;

        t.y = ui->maps->Tiles[i].y;



        m.Tiles.append(t);

    }







        QFile f(filename);



         if(!f.open(QIODevice::WriteOnly))

         {



         }else

         {

             QDataStream out(&f);

             out.setVersion(QDataStream::Qt_4_8);



             out << m.Tiles;



         }



        f.flush();

        f.close();

How can I fix this problem and serialize?

edited Nov 23 '18 at 14:29

asked Nov 23 '18 at 10:49

giovanni mannuoio

I have a problem during serialization with a simple Managed Structure.

My Class Header

class MappySaver

{



public:

    MappySaver();



    //structure

    struct Tile

    {

    public:

        int ID;

        int x,y,w,h;

        QRect rect;

    };



    QList<Tile> Tiles;

    QObject t;

    Tile tile;



};



QDataStream& operator << (QDataStream& s, const MappySaver::Tile& tile);

QDataStream& operator >> (QDataStream& s, MappySaver::Tile& tile);





#endif // MAPPYSAVER_H

and source cpp

   QDataStream &operator<<(QDataStream &s, const MappySaver::Tile& tile)

{

    s << tile;

    return s;

}

When I try to compile this, I get this error:

error: no match for 'operator<<' (operand types are 'QDataStream' and 'const MappySaver::Tile')

template <typename T> //QDataStream.h

QDataStream& operator<<(QDataStream& s, const QList<T>& l)

{

    s << quint32(l.size());

    for (int i = 0; i < l.size(); ++i)

        s << l.at(i);

    return s;

}

I use this class to serialize a list.
On the main form, I have a widget with the same data.

And I use this method for try to serialize.

QString filename = QFileDialog::getSaveFileName(this,

                                                tr("Seleziona il file da salvare"),"",

                                            tr("File Mappa (*.mp2d)"));



MappySaver::Tile t;

    MappySaver m;





    for(int i = 0; i < ui->maps->Tiles.count(); i++)

    {

        t.ID = ui->maps->Tiles[i].ID;

        t.h = ui->maps->Tiles[i].h;

        t.rect = ui->maps->Tiles[i].rect;

        t.w = ui->maps->Tiles[i].w;

        t.x = ui->maps->Tiles[i].x;

        t.y = ui->maps->Tiles[i].y;



        m.Tiles.append(t);

    }







        QFile f(filename);



         if(!f.open(QIODevice::WriteOnly))

         {



         }else

         {

             QDataStream out(&f);

             out.setVersion(QDataStream::Qt_4_8);



             out << m.Tiles;



         }



        f.flush();

        f.close();

How can I fix this problem and serialize?

c++ qt serialization qdatastream

edited Nov 23 '18 at 14:29

asked Nov 23 '18 at 10:49

giovanni mannuoio

edited Nov 23 '18 at 14:29

asked Nov 23 '18 at 10:49

giovanni mannuoio

edited Nov 23 '18 at 14:29

asked Nov 23 '18 at 10:49

giovanni mannuoio

asked Nov 23 '18 at 10:49

giovanni mannuoio

asked Nov 23 '18 at 10:49

giovanni mannuoio

At first glance the compiler tells you what's wrong. You wrote functions for MappySaver but pass MappySaver::Tile as argument.

– vahancho
Nov 23 '18 at 10:59

just create the function QDataStream& operator << (QDataStream& s, const MappySever::Tile& tile);

– Alexander Chernin
Nov 23 '18 at 11:48

@AlexanderChernin i have an error Segmentation Fault.

– giovanni mannuoio
Nov 23 '18 at 14:09

1

Yep, you're getting recursion there. The function is calling itself. More appropriately, you might be wanting to output individual << tile.ID, tile.x, etc?

– TrebuchetMS
Nov 23 '18 at 14:43

1

@TrebuchetMS Yea! Work! Tanks a lot Trebuchet. i have changend whit your example and work! image.ibb.co/f0FB5V/Immagine.png

– giovanni mannuoio
Nov 23 '18 at 15:09

|
show 4 more comments

At first glance the compiler tells you what's wrong. You wrote functions for MappySaver but pass MappySaver::Tile as argument.

– vahancho
Nov 23 '18 at 10:59

just create the function QDataStream& operator << (QDataStream& s, const MappySever::Tile& tile);

– Alexander Chernin
Nov 23 '18 at 11:48

@AlexanderChernin i have an error Segmentation Fault.

– giovanni mannuoio
Nov 23 '18 at 14:09

1

Yep, you're getting recursion there. The function is calling itself. More appropriately, you might be wanting to output individual << tile.ID, tile.x, etc?

– TrebuchetMS
Nov 23 '18 at 14:43

1

@TrebuchetMS Yea! Work! Tanks a lot Trebuchet. i have changend whit your example and work! image.ibb.co/f0FB5V/Immagine.png

– giovanni mannuoio
Nov 23 '18 at 15:09

At first glance the compiler tells you what's wrong. You wrote functions for MappySaver but pass MappySaver::Tile as argument.

– vahancho
Nov 23 '18 at 10:59

just create the function QDataStream& operator << (QDataStream& s, const MappySever::Tile& tile);

– Alexander Chernin
Nov 23 '18 at 11:48

@AlexanderChernin i have an error Segmentation Fault.

– giovanni mannuoio
Nov 23 '18 at 14:09

Yep, you're getting recursion there. The function is calling itself. More appropriately, you might be wanting to output individual << tile.ID, tile.x, etc?

– TrebuchetMS
Nov 23 '18 at 14:43

@TrebuchetMS Yea! Work! Tanks a lot Trebuchet. i have changend whit your example and work! image.ibb.co/f0FB5V/Immagine.png

– giovanni mannuoio
Nov 23 '18 at 15:09

|
show 4 more comments

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