强制Dart类型实现接口

Question

I have a map of strings to types in Dart eg animals = <String, Type>{'cat':CatType, 'dog':DogType} which I modify at runtime. Is there a way to ensure that types added to this map implement a particular interface, either at compile-time or runtime? Something like

animals = <String, Type<? implements AnimalType>>{...}

or during runtime,

void register(name, type):
  if type implements AnimalType:
    animals[name] = type

Answer 1

No, not really.

The Type class isn't generic, so you can't have a constrain on that.

You can use the dart:mirrors library to check whether a Type object represents a class that implements another type, but it's most likely not worth the effort.