Modernes C++ programmieren

// https://godbolt.org/z/aj8cnox4f 
#include <iostream>

using std::ostream; using std::cout;
struct Basis2 {
    int acht_ = 8;
    virtual int wert() const          // virtuelle Methode
        { return acht_; }
    void print(ostream& os) const
        { os << wert() << "\n"; }
};
struct Wert2 : public Basis2 {
    int zehn_ = 10;
    virtual int wert() const override // überschreiben
        { return zehn_; }
};
int main() {
    Wert2 we2{}; we2.print(cout);     // verwenden
}