DASM(std::string filename, std::function<void(unsigned int, unsigned int)> f = nullptr);

if(f!=nullptr)
  f(i,decodedInstructionsCount);

std::function<void(unsigned int,unsigned int)> get_f()
    {
        std::function<void(unsigned int,unsigned int)> ret = std::bind(&LoadWindow::pb_next,_2,_1);
        return ret;
    }

void LoadWindow::pb_next(unsigned int now, unsigned int max)
{
    this->m_progressbar.set_fraction(((double)now/(double)max));
}