/**
 * Copyright (c) 2019-present Houfeng
 * @author Houfeng <admin@xhou.net>
 */
export declare function copyTo<T1 = any, T2 = T1>(from: T1, to: T2): void;
export declare function assign<T1 = any, T2 = T1>(to: T1, from: T2): void;
export declare function select<T = any, R = any>(obj: T, keys: string[]): R;
export declare function requestFullscreen(element: any): any;