获取两个接口类型中的差值属性

type Foo = {
  a: string;
  b: number;
}
type Bar = {
  a: string;
  c: boolean
}

type Result1 = Diff<Foo, Bar> // { b: number, c: boolean }
type Result2 = Diff<Bar, Foo> // { b: number, c: boolean }

// 答案 1
type Diff<O, O1> = Omit<O & O1, keyof (O | O1)>

// 答案 2
type Diff<O, O1> = {
  [K in keyof (O & O1) as K extends keyof (O | O1) ? never : K]: (O1 & O)[K]
}