why this simple program doesn't run?

[Hesam]

Hi, I've written this simple program but it doesn't run. it doesn't show error but after build and run only shows "exited with code 0" instead of some strings whixh i've written in main body.

#ifndef mainwindow_H
#define mainwindow_H

class mainwindow
{
private:
        double a;
        double b;

public:
        mainwindow()
        {
            a = 0.0;
            b = 0.0;
        }

        mainwindow(double x, double y)
        {
            a = x;
            b = y;
        }

        void setA(double x)
        {
            a = x;
        }

        void setB(double y)
        {
            b = y;
        }

        double getA()
        {
            return a;
        }

        double getB()
        {
            return b;
        }

        void add(double x, double y)
        {
            a = x + y;
        }

        void sub(double x, double y)
        {
            a = x - y;
        }

        void mul(double x, double y)
        {
            a = x * y;
        }

        void div(double x, double y)
        {
            a = x / y;
        }
};

#endif 

#include <iostream>
#include "mainwindow.h"

int main()
{
    std::cout << "Program starts. . ." << std::endl;

    mainwindow test1;
    mainwindow test2(0.666, 0.875);

    std::cout << "A = " << test1.getA() << std::endl;
    std::cout << "B = " << test2.getB() << std::endl;

    test1.setB(test2.getB());
    test2.setA(test1.getA());

    std::cout << "A = " << test1.getA() << std::endl;
    std::cout << "B = " << test2.getB() << std::endl;

    return 0;

} 

[divanov]

This is not really Qt application, but it works fine.

$ qmake-qt4 -project
QFileInfo::absolutePath: Constructed with empty filename
$ qmake-qt4 
$ make
g++ -c -pipe -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fstack-protector --param=ssp-buffer-size=4 -m64 -mtune=generic -Wall -W -D_REENTRANT -DQT_NO_DEBUG -DQT_GUI_LIB -DQT_CORE_LIB -I/usr/lib64/qt4/mkspecs/linux-g++ -I. -I/usr/include/QtCore -I/usr/include/QtGui -I/usr/include -I. -I. -o main.o main.cpp
g++ -Wl,-O1 -o nonqt main.o     -lQtGui -lQtCore -lpthread 
$ ./nonqt 
Program starts. . .
A = 0
B = 0.875
A = 0
B = 0.875