import { _Pick } from './Pick';
import { Depth } from './_Internal';
import { Key } from '../Any/Key';
import { PatchFlat } from './Patch';
import { BuiltIn } from '../Misc/BuiltIn';
/**
 * @hidden
 */
export declare type ReadonlyFlat<O> = {
    +readonly [K in keyof O]: O[K];
} & {};
/**
 * @hidden
 */
export declare type ReadonlyDeep<O> = {
    +readonly [K in keyof O]: O[K] extends BuiltIn ? O[K] : ReadonlyDeep<O[K]>;
};
/**
 * @hidden
 */
export declare type ReadonlyPart<O extends object, depth extends Depth> = {
    'flat': ReadonlyFlat<O>;
    'deep': ReadonlyDeep<O>;
}[depth];
/**
 * @hidden
 */
export declare type _Readonly<O extends object, K extends Key, depth extends Depth> = PatchFlat<ReadonlyPart<_Pick<O, K>, depth>, O>;
/**
 * Make some fields of `O` readonly (deeply or not)
 * @param O to make readonly
 * @param K (?=`Key`) to choose fields
 * @param depth (?=`'default'`) to do it deeply
 * @returns [[Object]]
 * @example
 * ```ts
 * ```
 */
export declare type Readonly<O extends object, K extends Key = Key, depth extends Depth = 'flat'> = O extends unknown ? _Readonly<O, K, depth> : never;