/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */
/**
 * Coerces a value to an array of trimmed non-empty strings.
 * Any input that is not an array, `null` or `undefined` will be turned into a string
 * via `toString()` and subsequently split with the given separator.
 * `null` and `undefined` will result in an empty array.
 * This results in the following outcomes:
 * - `null` -&gt; `[]`
 * - `[null]` -&gt; `["null"]`
 * - `["a", "b ", " "]` -&gt; `["a", "b"]`
 * - `[1, [2, 3]]` -&gt; `["1", "2,3"]`
 * - `[{ a: 0 }]` -&gt; `["[object Object]"]`
 * - `{ a: 0 }` -&gt; `["[object", "Object]"]`
 *
 * Useful for defining CSS classes or table columns.
 * @param value the value to coerce into an array of strings
 * @param separator split-separator if value isn't an array
 */
export declare function coerceStringArray(value: any, separator?: string | RegExp): string[];