Ошибка при запуске ASSERT: "d" in file . , line 120. Все, что есть внутри

#ifndef MYWIND_H
#define MYWIND_H
 
#include <QDialog>
#include <QWidget>
#include <QLabel>
#include <QLineEdit>
#include <QPushButton>
#include <QHBoxLayout> //горизонт
#include <QVBoxLayout> //вертикаль
 
class MyWind : public QDialog
{
    Q_OBJECT //макрос
 
public:
    MyWind(QWidget *parent=0); //конструктор
private:
    QLabel *lbl;
    QLineEdit *line;
    QPushButton *one;
    QPushButton *two;
    QPushButton *three;
    QPushButton *four;
    QPushButton *five;
    QPushButton *six;
    QPushButton *seven;
    QPushButton *eight;
    QPushButton *nine;
    QPushButton *zero;
    QPushButton *point;
    QPushButton *reset;
    QPushButton *plus;
    QPushButton *minus;
    QPushButton *div;
    QPushButton *mult;
 
 
 
 
};
 
#endif // MYWIND_H

#include "MyWind.h"
 
MyWind::MyWind(QWidget *parent) : QDialog(parent)
{
    lbl = new QLabel("0");
    line = new QLineEdit("0");
 
    one = new QPushButton("1");
    two = new QPushButton("2");
    three = new QPushButton("3");
    four = new QPushButton("4");
    five = new QPushButton("5");
    six = new QPushButton("6");
    seven = new QPushButton("7");
    eight = new QPushButton("8");
    nine = new QPushButton("9");
    zero = new QPushButton("0");
 
    reset = new QPushButton("c");
    plus = new QPushButton("+");
    minus = new QPushButton("-");
    div = new QPushButton("/");
    mult = new QPushButton("*");
 
    QHBoxLayout *lay1 = new QHBoxLayout;
    lay1->addWidget(lbl);
    lay1->addWidget(line);
 
    QVBoxLayout *lay2 = new QVBoxLayout;
    lay2->addWidget(one);
    lay2->addWidget(four);
    lay2->addWidget(seven);
    lay2->addWidget(zero);
 
    QVBoxLayout *lay3 = new QVBoxLayout;
    lay3->addWidget(two);
    lay3->addWidget(five);
    lay3->addWidget(eight);
    lay3->addWidget(point);
 
    QVBoxLayout *lay4 = new QVBoxLayout;
    lay4->addWidget(three);
    lay4->addWidget(six);
    lay4->addWidget(nine);
    lay4->addWidget(reset);
 
    QHBoxLayout *lay5 = new QHBoxLayout;
    lay5->addWidget(plus);
    lay5->addWidget(minus);
 
    QHBoxLayout *lay6 = new QHBoxLayout;
    lay6->addWidget(div);
    lay6->addWidget(mult);
 
    QVBoxLayout *lay8 = new QVBoxLayout;
    lay8->addLayout(lay5);
    lay8->addLayout(lay6);
 
    QHBoxLayout *lay7 = new QHBoxLayout;
    lay7->addLayout(lay2);
    lay7->addLayout(lay3);
    lay7->addLayout(lay4);
    lay7->addLayout(lay8);
 
 
    QVBoxLayout *main = new QVBoxLayout;
    main->addLayout(lay1);
    main->addLayout(lay7);
 
    setLayout(main);
    setWindowTitle("Калькулятор");
 
}

#include <QApplication>
#include "MyWind.h"
 
int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
 
    MyWind *wind = new MyWind();
    wind->show();
 
 
    return a.exec();
}