/**
 * @packageDocumentation
 * @module Array
 */
import { PredicateFn } from '../types/generic-methods';
import { OperatorFunction } from 'rxjs';
/**
 * Returns an Observable that emits a boolean when all values in the source array return truthy using Array.every.
 * When working with data, if the array contains numbers `0` will be returned as a value to the [[PredicateFn]], but all
 * other falsy values will be ignored
 *
 * @category Query
 *
 * @typeParam T Type of value contained in the source Array or Set
 *
 * @param predicate Optional [[PredicateFn]] used to get a truthy value of Array values
 *
 * @example
 * Returns a boolean where every string item in the Array is truthy
 * ```ts
 * const input = [ ['', '', ''], ['', 'Hello', 'RxJS'], ['Hello', 'RxJS', 'Ninja'] ];
 * from(input).pipe(every()).subscribe();
 * ```
 * Output: `false, false, true`
 *
 * @example
 * Returns a boolean where every string item in the Array length `< 4`
 * ```ts
 * const input = [ ['', '', ''], ['', 'Foo', 'Bar'], ['Foo', 'Bar', 'Baz'] ];
 * from(input).pipe(every(v => v.length < 4)).subscribe();
 * ```
 * Output: `false, false, true`
 *
 * @example
 * Returns a boolean where every number in the array is less than `2`
 * ```ts
 * const input = [ [1, 0, 1, 0, 1, 0], [1, 0, 2, 1, 0, 2], [0, 1, 0, 1, 0, 2] ];
 * from(input).pipe(every(v => v < 2)).subscribe();
 * ```
 * Output: `true, false, false`
 *
 * @returns An Observable that emits a boolean when all values in source array return truthy
 */
export declare function every<T extends unknown>(predicate?: PredicateFn<T>): OperatorFunction<Iterable<T>, boolean>;