template<class T>
class TreapNode{
public:

    // STEP-BY-STEP

    static void loopLatency();
    static void changeLoopState();
    void changeStepByStepMode();
    void setDisableStepMode();

private:
    static bool stepLoopSwitcher;
    static bool stepButStepEnable;

};
template<class T>
void TreapNode<T>::changeLoopState(){
    stepLoopSwitcher = false;
}

template<class T>
void TreapNode<T>::changeStepByStepMode(){
    stepButStepEnable = true;
}

template<class T>
void TreapNode<T>::setDisableStepMode(){
    stepButStepEnable = false;
}

template<class T>
void TreapNode<T>::loopLatency(){
    qDebug() << "Loop latency for step-by-step started" << endl;
    for( ; ; ) {
        QApplication::processEvents();
        if(stepLoopSwitcher == false) break;
    }
    stepLoopSwitcher = true;
}

void MainWindow::onStepTreapDrawingButtonClicked() {
    //TreapNode<int>::changeLoopState(); // если здесь откоментрировать то падает
}
//:-1: ошибка: symbol(s) not found for architecture x86_64
//:-1: ошибка: linker command failed with exit code 1 (use -v to see invocation)