type DeepReadonly<T>: T extends Builtin ? T : T extends Map<infer K, infer V> ? ReadonlyMap<DeepReadonly<K>, DeepReadonly<V>> : T extends ReadonlyMap<infer K, infer V> ? ReadonlyMap<DeepReadonly<K>, DeepReadonly<V>> : T extends WeakMap<infer K, infer V> ? WeakMap<DeepReadonly<K>, DeepReadonly<V>> : T extends Set<infer U> ? ReadonlySet<DeepReadonly<U>> : T extends ReadonlySet<infer U> ? ReadonlySet<DeepReadonly<U>> : T extends WeakSet<infer U> ? WeakSet<DeepReadonly<U>> : T extends Promise<infer U> ? Promise<DeepReadonly<U>> : T extends Ref<infer U, unknown> ? Readonly<Ref<...>> : T extends object ? { readonly [K in (...)]: (...) } : Readonly<...>;