import type { CustomOptions, CustomValidate } from "../custom";
/**
 * Determines if the input is an integer.
 *
 * @param input - The value to check.
 * @param validate - Additional validation to run against the input if it is an integer. Default is `undefined`.
 * @returns `true` if the input is an integer, `false` otherwise.
 */
export declare function isInteger(input: unknown, validate?: CustomValidate<number>): input is number;
export type IntegerOptions = Omit<CustomOptions<number>, "typecheck">;
/**
 * Verifies that the input is an integer, and returns it.
 * If the input is not an integer, the fallback value is returned.
 *
 * @param input The value to check.
 * @param fallback The value to return if the input is not an integer. Default is `null`.
 * @returns The integer value of the input, or the fallback if the input is not an integer.
 */
export declare function integer(input: unknown, fallback: number, options?: IntegerOptions): number;
export declare function integer(input: unknown, fallback?: number | null | undefined, options?: IntegerOptions): number | null;