#include <iostream>

using namespace std;

constexpr int factorial(int x)
{
    return x ? x * factorial(x - 1) : 1;
}

constexpr int fibonacci(int x)
{
    return (x == 0 || x == 1) ? x : fibonacci(x - 1) + fibonacci(x - 2);
}

constexpr int binary(int x)
{
    return x == 0 ? 0 : x % 10 + 2 * binary(x / 10);
}

int main ()
{
    constexpr int fct = factorial(5);
    constexpr int fbn = fibonacci(10);
    constexpr int bin = binary(10000001);

    cout << fct << '\n';
    cout << fbn << '\n';
    cout << bin << '\n';

    return 0;
}

#include <QtCore>                                                                                                                            
#include <QtGui>                                                                                                                             
                                                                                                                                             
Q_DECLARE_METATYPE(QList<int>)                                                                                                               
Q_DECLARE_METATYPE(QList<QLabel*>)                                                                                                           
                                                                                                                                             
int main(int argc, char *argv[])                                                                                                             
{                                                                                                                                            
    QApplication a(argc, argv);                                                                                                              
                                                                                                                                             
    QList<QString> list1;                                                                                                                    
    list1 <<"String1" <<"String2";                                                                                                           
                                                                                                                                             
    QList<int> list2;                                                                                                                        
    list2 << 10 << 20;                                                                                                                       
                                                                                                                                             
    QList<QLabel*> list3;                                                                                                                    
    list3 << new QLabel("LB1") << new QLabel("LB2");                                                                                         
                                                                                                                                             
    QVariant v2;                                                                                                                             
    v2.setValue(list2);                                                                                                                      
                                                                                                                                             
    QVariant v3;                                                                                                                             
    v3.setValue(list3);                                                                                                                      
                                                                                                                                             
    QVariantList varList;                                                                                                                    
    varList << QVariant(list1) << v2 << v3;                                                                                                  
                                                                                                                                             
    return 0;                                                                                                                                
}