//#region src/predicate/is-in.d.ts
/**
 * Checks whether `key` exists in `object` — including inherited properties, as
 * the `in` operator does — and acts as a type guard that narrows the **object**
 * to include that property, so it can be accessed safely afterwards. The
 * argument order mirrors the native `key in object` expression. It also guards
 * against prototype-pollution keys (`__proto__`, `constructor`).
 *
 * To narrow the **key** instead of the object (e.g. when validating a union of
 * candidate keys), use {@link isKeyIn}.
 * @param key - The property key to look for.
 * @param object - The object to check.
 * @returns `true` if `key` is in `object` (own or inherited); narrows `object`
 * to additionally hold `key`.
 * @example
 * // Narrows an `unknown` value so the property can be read
 * const data: unknown = {foo: 1};
 * if (isIn('foo', data)) {
 *   data.foo; // accessible — `data` is now `Record<'foo', unknown>`
 * }
 * @example
 * // Inherited properties are found too
 * isIn('toString', {});
 * // true
 */
declare const isIn: <Key extends PropertyKey, ObjectType>(key: Key, object: ObjectType) => object is ObjectType & Record<Key, unknown>;
//#endregion
export { isIn };