ccbabi

> ```ts > type Foo = { > a?: number; > b: string; > c?: boolean; > } > > // 测试用例 > type SomeRequired = SetRequired; > // type...

```ts type Includes = ((...r: T) => void) extends ( f: infer F, ...r: infer R ) => void ? unknown extends F ? false : E extends F ?...

```ts type Head = Extract; // 你的实现代码 // 测试用例 type H0 = Head; // never type H1 = Head; // 1 type H2 = Head; // 3 ```

**6.1 NativeFlat** ```ts type NaiveFlat = T[number] extends infer U // 你的实现代码 ? U extends any[] ? U[number] : U : never; // 测试用例： type NaiveResult = NaiveFlat; // NaiveResult的结果：...

```ts interface Foo { [key: string]: any; [key: number]: any; bar(): void; } type RemoveIndexSignature = { [ K in keyof T as K extends `${infer S}` ? S :...