import { FunctionArguments } from './types';
export declare function runIfFn<T, U>(valueOrFn: T | ((...fnArgs: U[]) => T), ...args: U[]): T;
export declare function once(fn?: Function | null): (this: any, ...args: any[]) => any;
export declare const warn: (this: any, ...args: any[]) => any;
export declare function callAllHandlers<T extends (event: any) => void>(...fns: (T | undefined)[]): (event: FunctionArguments<T>[0]) => void;
export declare function canUseDOM(): boolean;
export declare const isBrowser: boolean;