import { IfIndexType, Key, Nil, ValueIteratee } from '../interfaces';
/**
 * Creates an object composed of keys generated from the results of running each element of `collection` thru `iteratee`. The corresponding value of each key is the last element responsible for generating the key.
 *
 * Contribution to minified bundle size, when it is the only function imported:
 * - Lodash: 14,323 bytes
 * - Micro-dash: 265 bytes
 */
export declare function keyBy<T, K extends Key>(array: T[] | Nil, iteratee: ValueIteratee<T, K>): IfIndexType<K, {
    [key in K]: T;
}, {
    [key in K]?: T;
}>;
export declare function keyBy<T, K extends Key>(object: T | Nil, iteratee: ValueIteratee<T[keyof T], K>): IfIndexType<K, {
    [key in K]: T[keyof T];
}, {
    [key in K]?: T[keyof T];
}>;