import { Point } from './types';
type Diff<T, U> = T extends U ? never : T;
export declare function assertIsNonNullable<T>(value?: T, error?: Error): asserts value is NonNullable<T>;
export declare const isNullable: <I>(i: I | null | undefined) => i is null | undefined;
export declare const isUndefined: <I>(i: I | undefined) => i is undefined;
export declare const isDefined: <I>(i: I | undefined) => i is Diff<I, undefined>;
export declare const isNonNullable: <I>(i: I | null | undefined) => i is Diff<I, null | undefined>;
export declare function getIsMouseEvent(event: MouseEvent | TouchEvent): event is MouseEvent;
export declare function getIsTouchEvent(event: MouseEvent | TouchEvent): event is TouchEvent;
export declare function isTouchDevice(): boolean;
/**
   * Method will check if 'child' node element is a child of
   * parent node with class 'className'
   * @param className
   * @param child
   */
export declare function isParentElement(className: string, child: EventTarget): boolean;
export declare function length(vector2d: Point): number;
export declare const preventDefault: (event: Event) => void;
export {};