import type { CustomOptions, CustomValidate } from "../custom/index.ts";
/**
 * Determines whether the input is a Blob.
 *
 * @param input The value being checked.
 * @param validate The validation function.
 * @returns `true` if the input is a Blob, `false` otherwise.
 */
export declare function isBlob(input: unknown, validate?: CustomValidate<Blob>): input is Blob;
export type BlobOptions = Omit<CustomOptions<Blob>, "typecheck">;
/**
 * Verifies that the input is a Blob.
 *
 * @param input The value to check.
 * @param fallback The value to return if the input is not a Blob. Default is `null`.
 * @param options Customization options.
 * @returns The input if it is a Blob; the fallback otherwise.
 */
export declare function blob(input: unknown, fallback: Blob, options?: BlobOptions): Blob;
export declare function blob(input: unknown, fallback?: Blob | null | undefined, options?: BlobOptions): Blob | null;