更短的写法<key extends =“”keyof =“”discriminatedmap =“keyof”discriminatedmap =“”>？

Question

我非常依赖ADT来建模我的数据。我发现自己一遍又一遍地写Key extends keyof DiscriminatedMap = keyof DiscriminatedMap。是否有更短的方式来声明相同的内容？

type DiscriminatedUnion<Key extends keyof DiscriminatedMap = keyof DiscriminatedMap> = 
  DiscriminatedMap[Key] & { kind: Key }

type DiscriminatedMap = {
  kindA: { someRecordType: string }
  kindB: { someOtherRecordType: number }
}