Modernes C++ programmieren

//#(compile) c++; compiler:g132; options:-O3 -std=c++23; libs:-
// https://godbolt.org/z/x1dq1Wof6 
#include <iostream>
#include <typeinfo>
#include <typeindex>
#include <map>
#include <string>
struct Base {
    virtual ~Base() {}
};
struct Derived_One : public Base {};
struct Derived_Two : public Base {};
int main() {
  using std::string; using std::cout; using std::type_index;
  std::map<std::type_index, string> namen {
      { type_index(typeid(int)), "int" },
      { type_index(typeid(double)), "double" },
      { type_index(typeid(Base)), "Base" },
      { type_index(typeid(Derived_One)), "Derived_One" },
      { type_index(typeid(Derived_Two)), "Derived_Two" },
      { type_index(typeid(string)), "string" },
      { type_index(typeid(string::const_iterator)), "string" },
  };
  namen[type_index(typeid(namen))] = "namen-map";
  int ganz;
  double fliessend;
  Base base{};
  Base *one = new Derived_One{};
  Base *two = new Derived_Two{};
  // typeid.name() ist implementierungs- und laufzeitabhängig:
  cout << typeid(ganz).name() << '\n';      // Bei mir: i
  cout << typeid(fliessend).name() << '\n'; // Bei mir: d
  cout << typeid(base).name() << '\n';      // Bei mir: 4Base
  cout << typeid(*one).name() << '\n';      // Bei mir: 11Derived_One
  cout << typeid(*two).name() << '\n';      // Bei mir: 11Derived_Two
  cout << typeid(string).name() << '\n';    // Bei mir: Ss
  cout << typeid(string{"Welt"}.begin()).name() << '\n';
      // Bei mir: N9__gnu_cxx17__normal_iteratorIPcSsEE
  cout << typeid(namen).name() << '\n';
      // Bei mir: St3mapISt10type_indexSsSt4lessIS0_ESaISt4pairIKS0_SsEEE
  cout << typeid(666/0).name() << '\n'; // Ausdruck wird nicht ausgeführt! Bei mir: i
  // type_index macht type_infos vergleichbar:
  cout << namen[type_index(typeid(ganz))] << '\n';      // Ausgabe: int
  cout << namen[type_index(typeid(fliessend))] << '\n'; // Ausgabe: double
  cout << namen[type_index(typeid(base))] << '\n';      // Ausgabe: Base
  cout << namen[type_index(typeid(*one))] << '\n';      // Ausgabe: Derived_One
  cout << namen[type_index(typeid(*two))] << '\n';      // Ausgabe: Derived_Two
  cout << namen[type_index(typeid(string))] << '\n';    // Ausgabe: string
  cout << namen[type_index(typeid(namen))] << '\n';     // Ausgabe: namen-map
}