/**
 * @packageDocumentation
 * @module Array
 */
import { OperatorFunction, Subscribable } from 'rxjs';
/**
 * Returns an Observable number or array of numbers. These are the index numbers of first truthy value in the source
 * array using Array.lastIndexOf
 *
 * @category Query
 *
 * @typeParam T The input type of the source Array or Set
 *
 * @param input A value or array of values to get the index of in the source array
 * @param fromIndex Optional index to start searching from in the array
 *
 * @example
 * Returns the last index of the word `RxJS` in the array
 * ```ts
 * const input = [ ['RxJS', 'Ninja', 'RxJS' ], ['Learn', 'RxJS'], ['Foo', 'Bar'] ];
 * from(input).pipe(lastIndexOf('RxJS')).subscribe();
 * ```
 * Output: `2, 1, -1`
 *
 * @example
 * Returns an array of the last index of the words `RxJS` and `Ninja` in the array
 * ```ts
 * const input = [ ['RxJS', 'Ninja', 'RxJS' ], ['Ninja', 'Learn', 'RxJS'], ['Foo', 'Bar'] ];
 * of(input).pipe(lastIndexOf(['RxJS', 'Ninja'])).subscribe()
 * ```
 * Output: `[2, 1], [0, 2], [-1, -1]`
 *
 * @example
 * Returns the last index of the word `RxJS` in the array starting from index `1`
 * ```ts
 * const input = [ ['RxJS', 'Ninja', 'RxJS', 'Ninja', 'Ninja' ], ['Learn', 'RxJS'], ['Foo', 'Bar'] ];
 * of(input).pipe(lastIndexOf('RxJS', 1)).subscribe()
 * ```
 * Output: `2, 1, -1`
 *
 * @example
 * Returns the last index of the word `RxJS` in the array comparing with lower case
 * ```ts
 * const input = [ ['RxJS', 'Ninja', 'RxJS'], ['Learn', 'RxJS'], ['Foo', 'Bar'] ];
 * of(input).pipe(lastIndexOf('rxjs', 0, v => v.toLowerCase())).subscribe()
 * ```
 * Output: `2, 1, -1`
 *
 * @returns Observable number or array of numbers containing the index of the last found value
 */
export declare function lastIndexOf<T extends unknown>(input: Subscribable<Iterable<T> | T> | Iterable<T> | T, fromIndex?: Subscribable<number> | number): OperatorFunction<Iterable<T>, number[]>;