dynamic_instance.dart

void main() {
  final dynamicInstance = createInstanceOf<Foo>();
  
  print(dynamicInstance);
}

T? createInstanceOf<T>() {
  final factories = <Type, T Function()>{
    Foo: () => Foo() as T, 
    Bar: () => Bar() as T,
  };
  
  final createInstance = factories[T];

  return createInstance?.call(); // Same as createInstance() but null safety
}

class Foo {}

class Bar {}