DeepKeysAndValuesImpl

type DeepKeysAndValuesImpl<T, TParent, TAcc> = unknown extends T ? 
  | TAcc
  | UnknownDeepKeyAndValue<TParent> : unknown extends T ? T : T extends string | number | boolean | bigint | Date ? TAcc : T extends ReadonlyArray<any> ? number extends T["length"] ? DeepKeyAndValueArray<TParent, T, TAcc> : DeepKeyAndValueTuple<TParent, T, TAcc> : keyof T extends never ? 
  | TAcc
  | UnknownDeepKeyAndValue<TParent> : T extends object ? DeepKeyAndValueObject<TParent, T, TAcc> : TAcc;