export declare const isArray: (arg: any) => arg is any[];
/** Whether the variable effective. */
export declare const isEffective: (variable: any) => boolean;
export declare const isBrowser: boolean;
/** Whether the environment support -webkit-line-clamp. */
export declare const isSupportNativeEllipsis: boolean;
/** Whether the environment support window.requestAnimationFrame. */
export declare const isSupportRequestAnimationFrame: boolean;