/**
 * Typescript aware null and undefined check. Makes sure type is narrowed when used in an array filter.
 *
 * @template T The type of the non-null and non-undefined items in the array.
 * @param {T | null | undefined} item The item to check for null or undefined.
 * @returns {item is T} A type predicate indicating whether the item is neither null nor undefined.
 *
 * @example
 * const mixedArray = [1, null, 2, undefined, 3];
 * const nonNilArray = mixedArray.filter(isNotNil);
 * // nonNilArray will be [1, 2, 3]
 */
export declare const isNotNil: <T>(item: T | null | undefined) => item is T;