Ping Gao

```ts type Has = T extends [infer H, ...infer R] ? Equal extends true ? true : Has : false; type Unique = T extends [...infer P, infer R] ?...

```ts type Join = T extends [ infer H, ...infer R ] ? H extends string ? R extends string[] ? R extends [] ? H : `${H}${U}${Join}` : never...

```ts type First = T extends [infer K, ...any[]] ? K : never; type PopFront = T extends [any, ...infer P] ? P : never; type Target = T extends...