/**
 * Check if value is undefined with type predictions.
 *
 * ```ts
 * const array: (string | undefined)[] = ['some', undefined];
 * const filteredArray: string[] = array.filter(notUndefined);
 * ```
 *
 * modified from https://www.typescriptlang.org/docs/handbook/advanced-types.html#user-defined-type-guards
 */
declare function notUndefined<TestValue>(value: TestValue | undefined): value is TestValue;
export default notUndefined;