C++ class like union

main.cpp

#include <iostream>

struct User {
    enum { AGE, NAME } tag;
    
    union {
        int    age;
        char * nik;
    };
    
    User(int age) {
        this -> tag = User::AGE;
        this -> age = age;
    }
    
    User(char * name) {
        this -> tag = User::NAME;
        this -> nik = name;
    }
    
    void
    print() {
        switch(this -> tag)
        {
            case User::AGE:  std::cout << this -> age << '\n'; break;
            case User::NAME: std::cout << this -> nik << '\n'; break;
        }
    }
};

int main(int argc, const char * argv[]) {
    
    User Andrey("menangen");
    User Andru(12);
    
    Andrey.print();
    Andru.print();
    
    std::cout << "Hello, User!\n";
    return 0;
}