export declare function isObject(value: any): value is Record<string, any>;
export declare function isFunction(value: any): value is (...args: any[]) => any;
export declare function isNil(value: unknown): value is undefined | null;
export declare function notNil<T>(value: T | undefined | null): value is T;
export declare function isDirectory(path: string): boolean;
export declare function isString(value: any): value is string;
export declare function isUndefined(value: any): value is undefined;