import { ValidatorFn } from '@angular/forms';
/**
 * @description
 * Validator that performs pattern matching against a string input that should NOT match the pattern.
 * Opposite of Angular's built-in pattern validator.
 *
 * @usageNotes
 *
 * ```typescript
 * const control = new FormControl('abc', notPattern(/[0-9]/));
 * console.log(control.errors); // null - valid because 'abc' does not contain numbers
 *
 * const control2 = new FormControl('abc123', notPattern(/[0-9]/));
 * console.log(control2.errors); // {notPattern: {requiredPattern: '/[0-9]/', actual: 'abc123'}} - invalid because it contains numbers
 * ```
 *
 * @param pattern A regular expression or string to match against
 * @returns A validator function that returns an error map with the `notPattern` property
 * if the validation check fails, otherwise `null`.
 */
export declare function notPattern(pattern: string | RegExp): ValidatorFn;