/** @private */
export declare const deepEqual: any;
/**
 * Checks process.title is not equal to 'browser'
 *
 * Set as 'browser' via build tools (e.g. webpack) to package
 * browser specific code to bundle
 *
 * see {@link https://github.com/derbyjs/derby-webpack/blob/main/createConfig.js#L95 | derby-webpack}
 */
export declare const isServer: boolean;
/** @private */
export declare function asyncGroup(cb: any): () => (err?: Error) => void;
/** @private */
export declare function castSegments(segments: Readonly<Array<string | number>>): (string | number)[];
/** @private */
export declare function contains(segments: any, testSegments: any): boolean;
/** @private */
export declare function copy(value: any): any;
/** @private */
export declare function copyObject(object: any): any;
/** @private */
export declare function deepCopy(value: any): any;
/** @private */
export declare function equal(a: any, b: any): boolean;
/** @private */
export declare function equalsNaN(x: any): boolean;
/** @private */
export declare function isArrayIndex(segment: string): boolean;
/** @private */
export declare function lookup(segments: string[], value: unknown): unknown;
/** @private */
export declare function mayImpactAny(segmentsList: string[][], testSegments: string[]): boolean;
/** @private */
export declare function mayImpact(segments: string[], testSegments: string[]): boolean;
/** @private */
export declare function mergeInto(to: any, from: any): any;
/** @private */
export declare function promisify<T = void>(original: any): () => Promise<T>;
/**
 * Conditionally require module only if in server process. No-op when called in browser.
 *
 * @param module
 * @param id
 * @returns module or undefined
 */
export declare function serverRequire(module: any, id: any): any;
/**
 * Use plugin only if invoked in server process.
 *
 * @param module
 * @param id
 * @param options - Optional
 * @returns
 */
export declare function serverUse(module: any, id: string, options?: unknown): any;
type Plugin<T extends {}, O> = (pluginHost: T, options: O) => void;
/**
 * Use plugin
 *
 * @param plugin
 * @param options - Optional options passed to plugin
 * @returns
 */
export declare function use<T extends {}, O>(this: T, plugin: Plugin<T, O>, options?: O): T;
export {};