/**
 * Generate GUID
 * @return {number}
 * @memberOf clay.core.util
 */
export declare function genGUID(): number;
/**
 * Relative path to absolute path
 * @param  {string} path
 * @param  {string} basePath
 * @return {string}
 * @memberOf clay.core.util
 */
export declare function relative2absolute(path: string, basePath: string): string;
/**
 * Extend properties to target if not exist.
 * @param  {Object} target
 * @param  {Object} source
 * @return {Object}
 * @memberOf clay.core.util
 */
export declare function defaults(target: any, source: any): any;
/**
 * @param  {Object|Array} obj
 * @param  {Function} iterator
 * @param  {Object} [context]
 * @deprecated
 */
export declare function each(obj: any, iterator: Function, context: any): void;
/**
 * Is object
 * @param obj
 * @memberOf clay.core.util
 */
export declare function isObject(obj: any): boolean;
/**
 * Is array like, which have a length property
 * @param obj
 * @memberOf clay.core.util
 */
export declare function isArrayLike(obj: any): obj is ArrayLike<any>;
export declare function isFunction(value: any): value is Function;
export declare function isString(value: any): value is string;
export declare function isNumber(value: any): value is number;
/**
 * @param obj
 * @return {}
 * @memberOf clay.core.util
 */
export declare function clone<T>(obj: T): T;
export declare function hasOwn(obj: any, key: string): boolean;
export declare function optional<T>(val: T, defaultVal: Exclude<T, undefined | null>): Exclude<T, null | undefined>;
export declare function keys(obj?: any): string[];
export declare const assign: {
    <T extends {}, U>(target: T, source: U): T & U;
    <T extends {}, U, V>(target: T, source1: U, source2: V): T & U & V;
    <T extends {}, U, V, W>(target: T, source1: U, source2: V, source3: W): T & U & V & W;
    (target: object, ...sources: any[]): any;
};
export declare function setCanvasSize(canvas: HTMLCanvasElement | OffscreenCanvas, width: number, height: number, pixelRatio?: number): void;
export declare const isArray: (arg: any) => arg is any[];
export declare function assert(cond: boolean, msg?: string): void;