import { type ArrayOrValue } from './../array/array';
import { type Maybe } from '../value/maybe.type';
/**
 * Pair of allowed/disallowed values.
 */
export interface AllowedSet<T> {
    /**
     * Values that are allowed. Hits against this set result in an initial true.
     */
    readonly allowed?: Maybe<Set<T>>;
    /**
     * Values that are disallowed. Hits against this set result in false.
     */
    readonly disallowed?: Maybe<Set<T>>;
}
/**
 * Determines whether the input values are "allowed" for the given {@link AllowedSet}.
 * A value is allowed if it matches the `allowed` set (or `allowed` is not specified)
 * and does not match the `disallowed` set.
 *
 * @param input - The value or array of values to check.
 * @param allowedSet - The allowed/disallowed configuration.
 * @returns `true` if the values are allowed.
 */
export declare function isAllowed<T>(input: ArrayOrValue<T>, allowedSet: AllowedSet<T>): boolean;