lst-0399-godb.cpp
//#(execute) c++; compiler:g132; options:-O3 -std=c++23; libs:-
// https://godbolt.org/z/eYY1js4Te
class Year : public Value { // von Klasse Value ableiten
public:
explicit Year(int v) : Value{v, 4} {} // Basisklasse initialisieren
};
class Month : public Value {
public:
explicit Month(int v) : Value{v, 2} {}
};
struct Day : public Value { // class-public entspricht struct
explicit Day(int v) : Value{v, 2} {}
};