Appending a QList<QStringList>

[Dummie1138]

I have the following code.

QStringList configorder;
for (int i = 0; i < ui->tableWidget_Configs->rowCount(); i++){
    configorder.append(ui->tableWidget_Configs->item(i,1)->text());
}
//Followed by a function that takes a QStringList

I want to swap from a QStringList to a QList<QStringList> so I can hold multiple variables into the same object.

QList<QStringList> configorder;
for (int i = 0; i < ui->tableWidget_Configs->rowCount(); i++){
    configorder.at(i).append(ui->tableWidget_Configs->item(i, 1)->text()); //Error
    configorder.at(i).append(ui->tableWidget_Configs->item(i, 2)->text());  //Error
    configorder.at(i).append(ui->tableWidget_Configs->item(i, 3)->text());  //Error
}
//Followed by a function that takes a QList<QStringList>

I am encountering this error.

error: no matching member function for call to 'append'
qlist.h:210:10: note: candidate function not viable: no known conversion from 'const QStringList' to 'QList<QString>' for object argument
qlist.h:211:10: note: candidate function not viable: no known conversion from 'const QStringList' to 'QList<QString>' for object argument

Per my understanding of C++, QList<QStringList> is being declared in a way such that QStringList has to be a const. I am unsure how to declare QList<QStringList> in such a way such that it has no const, since I did not declare it as such.

My workaround:

    QList<QStringList> configorder;
    for (int i = 0; i < ui->tableWidget_Configs->rowCount(); i++){
        QStringList stringList;
        stringList.append(ui->tableWidget_Configs->item(i,1)->text());
        stringList.append(ui->tableWidget_Configs->item(i,2)->text());
        stringList.append(ui->tableWidget_Configs->item(i,3)->text());
        configorder.append(stringList);
    }
//This works.

Furthermore, I am unsure why my workaround worked, while the original did not. I did not find any documentation on QList<QStringList> being always a const so I am unsure why original code did not work. Please let me know if more info is required.

[jsulm]

@Dummie1138 If you read documentation: https://doc.qt.io/qt-5/qlist.html#at you will see that at() returns a CONST reference. Simply use [] instead of at...

[JonB]

@Dummie1138
In addition to @jsulm. Your "workaround" is good. It takes advantage of void QList::append(const QList<T> &value), which allows you to append one list to another (of the same type) without iterating adding each member individually. You could even just go:

configorder.append( { ui->tableWidget_Configs->item(i,1)->text(), ui->tableWidget_Configs->item(i,2)->text(), ui->tableWidget_Configs->item(i,3)->text() } );