import { ComponentInstruction } from './instruction';
export { routerCanReuse, routerCanDeactivate, routerOnActivate, routerOnReuse, routerOnDeactivate } from './lifecycle_annotations_impl';
/**
 * Defines route lifecycle hook `CanActivate`, which is called by the router to determine
 * if a component can be instantiated as part of a navigation.
 *
 * <aside class="is-right">
 * Note that unlike other lifecycle hooks, this one uses an annotation rather than an interface.
 * This is because the `CanActivate` function is called before the component is instantiated.
 * </aside>
 *
 * The `CanActivate` hook is called with two {@link ComponentInstruction}s as parameters, the first
 * representing the current route being navigated to, and the second parameter representing the
 * previous route or `null`.
 *
 * ```typescript
 * @CanActivate((next, prev) => boolean | Promise<boolean>)
 * ```
 *
 * If `CanActivate` returns or resolves to `false`, the navigation is cancelled.
 * If `CanActivate` throws or rejects, the navigation is also cancelled.
 * If `CanActivate` returns or resolves to `true`, navigation continues, the component is
 * instantiated, and the {@link OnActivate} hook of that component is called if implemented.
 *
 * ### Example
 *
 * {@example router/ts/can_activate/can_activate_example.ts region='canActivate' }
 */
export declare var CanActivate: (hook: (next: ComponentInstruction, prev: ComponentInstruction) => Promise<boolean> | boolean) => ClassDecorator;