main.dart

class Animal {}

class Cat extends Animal {}

class Dog extends Animal {}

class Pencil {}

class Tool<A, B> {}

main() {
  List<Cat> catList = [Cat(), Cat(), Cat()];
  List<Dog> dogList = [Dog(), Dog(), Dog()];
  List<Animal> animalList = [...catList, ...dogList];
  
  for (final x in animalList) {
    print(x);
  }
  
  print(catList is List<Animal>); // true
  print(catList is List<Cat>); // true
  print(catList is List<Dog>); // false
  
  print(animalList is List<Cat>); // false
  
  print(catList is List<Pencil>); // false
  
  /// -----
  /// VÍCE GENERIKY, SLOŽITĚJŠÍ PŘÍKLAD
  print('-----');
  
  var a = Tool<Animal, Animal>();
  var b = Tool<Cat, Cat>();
  var c = Tool<Cat, Dog>();
  var d = Tool<Dog, Cat>();
  
  print(a is Tool<Animal, Animal>); // true
  print(b is Tool<Animal, Animal>); // true
  print(c is Tool<Animal, Animal>); // true
  print(d is Tool<Animal, Animal>); // true
  print(c is Tool<Dog, Cat>); // false
  print(c is Tool<Cat, Dog>); // true
}