vector<struct> serialization / deserialization

[RahibeMeryem]

Hi Gentlement,

I have ;

struct objectv1 {
        matrix<float, 0, 1 > obj_descriptor;
        string person_name;
        matrix<rgb_pixel> p_obj_chip;
        string notes;

    };

std::vector<objectv1> object_deteails;

How can I serialize and deserialize this in Qt world ?

stucked here for whole day ...

thx

[VRonin]

you have to create:

QDataStream &operator<<(QDataStream &, const T&); //serialise
QDataStream &operator>>(QDataStream &, T&); //de-serialise

for T being:

• std::vector
• string
• matrix
• rgb_pixel
• objectv1

for example:

template<class T>
QDataStream &operator<<(QDataStream& stream, const std::vector<T>& val){
stream << static_cast<quint32>(val.size());
for(auto& singleVal : val)
stream << singleVal;
return stream;
}
template<class T>
QDataStream &operator>>(QDataStream& stream, std::vector<T>& val){
quint32 vecSize;
val.clear();
stream >> vecSize;
val.reserve(vecSize);
T tempVal;
while(vecSize--){
stream >> tempVal;
val.push_back(tempVal);
}
return stream;
}
QDataStream &operator<<(QDataStream& stream, const objectv1& val){
return stream << val.obj_descriptor << val.person_name << val.p_obj_chip << val.notes;
}
QDataStream &operator>>(QDataStream& stream, objectv1& val){
return stream >> val.obj_descriptor >> val.person_name >> val.p_obj_chip >> val.notes;
}

I don't know what the other classes are so i'll leave it to you.

[RahibeMeryem]

I will try and let you know .

thnx a lot.

[RahibeMeryem]

@VRonin said in vector<struct> serialization / deserialization:

QDataStream &operator<<(QDataStream& stream, const objectv1& val){
return stream << val.obj_descriptor << val.person_name << val.p_obj_chip << val.notes;
}
QDataStream &operator>>(QDataStream& stream, objectv1& val){
return stream >> val.obj_descriptor >> val.person_name >> val.p_obj_chip >> val.notes;
}

it gave :

./widget.h:238:18: error: overloaded 'operator<<' must be a binary operator (has 3 parameters)
QDataStream &operator<<(QDataStream& stream, const pobjectv1& val){
^

I am missing something definitely. being a java girl for years , c++ looks like alien sometimes.. :)

[kshegunov]

@RahibeMeryem said in vector<struct> serialization / deserialization:

it gave :
./widget.h:238:18: error: overloaded 'operator<<' must be a binary operator (has 3 parameters)
QDataStream &operator<<(QDataStream& stream, const pobjectv1& val){

Show us what you got that generated that error, at least what is pobjectv1 and how you defined the operators. It's rather hard and futile to guess.

[RahibeMeryem]

@kshegunov Hi . here the codes:

struct personv1 {
        matrix<float, 0, 1 > obj_descriptor;
        string person_name;
        string notes;
        matrix<rgb_pixel> s_obj_chips;
       
    };
std::vector<personv1> person;


and:

template<class T>
    QDataStream &operator<<(QDataStream& stream, const std::vector<T>& val){
        stream << static_cast<quint32>(val.size());
        for(auto& singleVal : val)
        stream << singleVal;
        return stream;
}
    template<class T>
    QDataStream &operator>>(QDataStream& stream, std::vector<T>& val){
        quint32 vecSize;
        val.clear();
        stream >> vecSize;
        val.reserve(vecSize);
        T tempVal;
        while(vecSize--){
        stream >> tempVal;
        val.push_back(tempVal);
        }
        return stream;
}

QDataStream &operator<<(QDataStream& stream, const personv1& val){
    return stream << val.obj_descriptor << val.person_name << << val.notes << val.s_obj_chips ;

   }

    QDataStream &operator>>(QDataStream& stream, personv1& val){
    return stream >> val.obj_descriptor >> val.person_name >> val.notes >> val.s_obj_chips;
    }

[VRonin]

You are missing the operators for : matrix, string and rgb_pixel I don't know what those classes are so i can't write them for you