How to use QVector as a member of class

My class below

class MyWidget : public QWidget
{
    Q_OBJECT
public:
    ...
QVector<double> time; //1
QVector<double> other; //2
....
}

but I get error when compile. The program has unexpectedly finished and myprogram.exe crashed. I compile successfully when I delete line 1,2 in code above. Are there something wrong with my code? How could I use QVector as a member of class?