QCompleter - how to import data from file

I am quite new to Qt. I tried to find answers here but did not succeed so far. I have in a main.cpp file a vector of a complex struct and I would like to use it as an input for the QCompleter I have defined in a void function of my mainwindow.cpp that creates among other thing a QLineEdit to which I associate this QCompleter. How shall I transfer this vector to my completer ? Part of main.cpp:

//... l is a vector based on a struct containing, among other thing , string name.
QApplication a(argc, argv);
QStringList *LocationStringList=new QStringList;
for (int k=0;k!=l.size();k++)   {
    LocationStringList->append(QString::fromStdString(l[k].name));
}
MainWindow w;
w.show();

part of MainWindows.cpp :

void MainWindow::new()
{
    ...
    QCompleter *cmpt;
    cmpt=new QCompleter(LocationStringList,this);
    cmpt->setCaseSensitivity(Qt::CaseInsensitive);
    QLineEdit *locationLineEdit = new QLineEdit();
    locationLineEdit->setCompleter(cmpt);
    ...

It seems it does not know : LocationStringList

Solution

What have you tried? Normally, you can use it like this:

QStringList list;
for(auto& complexStructObject : complexStructList)
    list << complexStructObject.getStringForCompletion();

QCompleter* myCompleter = new QCompleter(list, this);

myLineEdit->setCompleter(myCompleter);

In your example, I would pass the list to your class:

// main.cpp

// above keeps unchanged
MainWindow w(LocationStringList);
w.show();
// at the end, do not forget to delete!! your string list is not managed; better yet use a unique_ptr

// MainWindow.h
#include <QStringList>

class MainWindow
{
Q_OBJECT
public:
    MainWindow(QStringList* stringList);

    // ...
};

// MainWindows.cpp
MainWindow::MainWindow(QStringList* stringList)
{
    QCompleter *cmpt;
    cmpt=new QCompleter(*stringList, this);
    cmpt->setCaseSensitivity(Qt::CaseInsensitive);
    QLineEdit *locationLineEdit = new QLineEdit();
    locationLineEdit->setCompleter(cmpt);
}

new is a reserved keyword, so you should probably just use your constructor