问题
In dart you can do
class Preference<T extends int>
to define a type constraint. But is there a way to define multiple constrains?
I tried
class Preference<T extends int, String>
But an error get's thrown when I try to pass a argument of type T to a function that excepts a String saying
The argument type 'T' can't be assigned to the parameter type 'String'
回答1:
No, Dart type parameters can only have a single constraint. There is no workaround.
来源：https://stackoverflow.com/questions/61820181/is-it-possible-to-have-multiple-type-constaints-on-a-generic-type