Trying to declare QVector in a QDialog header file

[pcheimets]

I want to declare a QVector in a header file so that I can use it throughout the functions in the class.
This seems so easy, and it works when I do it in a QMainWindow header, but it crashes ("Finishes unexpectedly") if I do the same thing in a QDialog header file. The code is below. If I uncomment the line: "//QVector<double> x,y;", the program compiles and crashes. I put the identical line in a QMainWindow header and it works exactly as I'd expect. The program runs, and the QVector is available to all of the functions in the MainWindow class. I assume I am missing something very basic.

This is on a MAC, QT5.5.5, Creator 3.5.1, Opensource

#ifndef GRAPH_H
#define GRAPH_H

#include <QDialog>
#include <QDesktopWidget>

namespace Ui {
class graph;
}

class graph : public QDialog
{
Q_OBJECT

public:
explicit graph(QWidget *parent = 0);
~graph();
//QVector<double> x,y;
void transfer_data(QVector<double> a, QVector<double> b);

private slots:
void on_makegraph1_clicked();

private:
Ui::graph *ui;

[mrjj]

Hi and welcome
Does it crash if you just have in ?
You dont do anything to it ?
also did you try as
QVector<double> x
QVector<double> y;

[jsulm]

Hi and welcome!
When does it crash? When it is started? When you create an instance of graph? When you show the graph dialog?
Why do you include QDesktopWidget?

[pcheimets]

It crashes just after I compile the program and before anything opens. The QDialog is called by a mainwindow, and the mainwindow doesn't even open.

I put the QDesktopWidget in because I was hoping it would help; that call is in the MainWindow header, and the QVector declaration works there.

I have tried declaring them separately (QVector<double> x; ...
That crashes as well. ("The program has unexpectedly finished.").

Thanks

Peter

[mrjj]

should also work in the dialog :)

--The QDialog is called by a mainwindow
can i see how u call it?

[pcheimets]

This is the calling statements. I tried ...show() instead, and got the same result.

graphWindow.transfer_data(x,y);

graphWindow.exec();

[mrjj]

@pcheimets said:
ok. and where do you declare it ?
is it same function ?
like

void Doti() {
graph graphWindow;
graphWindow.transfer_data(x,y);
graphWindow.exec();
}
graph graphWindow; should be in a class or function. Not in global scope.

what do transfer_data do ?
can you show inside ?

so in your sample, you send graphWindow 2 other lists ?
transfer_data(x,y); << - those are other list you send to the graphWindow?