construction_from_composite.vala

public class Person {
   private string _name;
   private int    _age;
   
   public Person(string name, int age) {
      _name = name;
      _age  = age;
   }
   
   public Person.from_gendered_person(GenderedPerson gp) {
      _name = gp.person().name();
      _age  = gp.person().age();
   }
   
   public string name() {
      return _name;
   }
   
   public int age() {
      return _age;
   }
}

public class GenderedPerson {
   private string _gender;
   private Person _person;
   
   public GenderedPerson(string name, int age, string gender) {
      _person = new Person(name, age);
      _gender = gender;
   }
   
   public Person person() {
      return _person;
   }
}

public void main() {
   GenderedPerson stephanie = new GenderedPerson("Stephanie", 33, "female");
   Person person = new Person.from_gendered_person(stephanie);
   print(person.name());
}