/*!
 * Copyright (c) 2020 Ville de Montreal. All rights reserved.
 * Licensed under the MIT license.
 * See LICENSE file in the project root for full license information.
 */
/**
 * A watch that can measure elapsed time using high-resolution real time
 */
export declare class Stopwatch {
    private hrstart?;
    private hrend?;
    /**
     * creates a new watch and start it
     */
    static startNew(): Stopwatch;
    /** tells if the watch is started */
    isStarted(): boolean;
    /** tells if the watch is stopped */
    isStopped(): boolean;
    /**
     * Starts the watch.
     * @throws Error if the watch is already started
     */
    start(): void;
    /**
     * Stops the watch.
     * @throws Error if the watch has not been started
     */
    stop(): void;
    /** resets the watch */
    reset(): void;
    /** resets the watch and start it again */
    restart(): void;
    /**
     * gets the elapsed time in nano seconds since the start
     * @throws Error if the watch has not been started
     */
    elapsedTimeInNanos(): bigint;
    /**
     * gets the elapsed time in milli seconds since the start
     * @throws Error if the watch has not been started
     */
    elapsedTimeInMS(): number;
    /** gets a string representation of the watch's state */
    toString(): string;
}