00459
Flatten
type Flatten<T extends any[]> = T extends [infer First, ...infer Rest] ? First extends any[] ? [...Flatten<First>, ...Flatten<Rest>]:[First, ...Flatten<Rest>]:T;
type Flatten<T extends any[]> = T extends [infer First, ...infer Rest] ? First extends any[] ? [...Flatten<First>, ...Flatten<Rest>]:[First, ...Flatten<Rest>]:T;