export type Unsubscribe = () => void;
/**
 * List of valid event args given `K`.
 */
export type EventArg<T, K extends keyof T> = T[K];
/**
 * An event emitter class we can use to manage hooks or other emittable data.
 * Take a type argument of shape Record<eventName, callBackData>
 *
 * A classified version of the MIT licensed https://robinpokorny.github.io/dead-simple/
 * With some type safety inspiration from https://github.com/serviejs/events
 */
export declare class EventEmitter<T> {
    private events;
    /**
     * Registers a listener that will be called when the named event is emitted
     * @returns An unsubscribe function that will turn off this listener.
     */
    on<K extends keyof T>(name: K, fn: (data: EventArg<T, K>) => void): Unsubscribe;
    /**
     * Registers a listener that will be called a single time when the named event
     * is emitted
     * @returns An unsubscribe function that will turn off this listener.
     */
    once<K extends keyof T>(name: K, fn: (data: EventArg<T, K>) => void): Unsubscribe;
    /**
     * Removes all event listeners for the given key
     * @returns void
     */
    off<K extends keyof T>(name: K): void;
    /**
     * Used to emit events to all registered hook listeners
     *
     * @private
     */
    emit<K extends keyof T>(name: K, data: EventArg<T, K>): void;
}