import { MessageFunctionType, Result } from '../types';
export interface IsBase64Errors {
    TARGET_ARGUMENT_NOT_A_STRING: MessageFunctionType;
}
export declare const IS_BASE64_ERRORS: IsBase64Errors;
/**
 * Checks whether the `target` is base64 encoded
 *
 * ### Example
 * ```
 * expect(isBase32('ZG======')).toBeTruthy()
 * ```
 *
 * @param target The target string
 */
export declare function isBase64(target: string, options?: any): Result<boolean | undefined>;