import type { CustomOptions, CustomValidate } from "../custom";
export declare const THREE_PART_VERSION_PATTERN: RegExp;
export type ThreePartVersion = `${number}.${number}.${number}`;
/**
 * Determines whether the input is a three-part version number.
 *
 * @param input The input to check.
 * @returns `true` if the input is a three-part version number, or `false` otherwise.
 */
export declare function isThreePartVersion(input: unknown, validate?: CustomValidate<ThreePartVersion>): input is ThreePartVersion;
export type ThreePartVersionOptions = Omit<CustomOptions<ThreePartVersion>, "typecheck">;
/**
 * Verifies that the input is a three-part version, and returns it.
 *
 * @param input The value to check.
 * @param fallback The value to return if the input is not a three-part version. Default is `null`.
 * @returns The three-part version value of the input, or the fallback if the input is not a three-part version.
 */
export declare function threePartVersion(input: unknown, fallback: ThreePartVersion, options?: ThreePartVersionOptions): ThreePartVersion;
export declare function threePartVersion(input: unknown, fallback?: ThreePartVersion | null | undefined, options?: ThreePartVersionOptions): ThreePartVersion | null;