export interface IStoppableStopwatch {
    /** Stop the given stopwatch. */
    stop(): void;
}
/**
 * Allows to measure keys of type `T` with a `Stopwatch`.
 *
 * Measure with {@link start}, {@link measure} or {@link measureAsync}, retrieve the final measurements with {@link get}.
 */
export declare class Measurements<T> {
    private measurements;
    /**
     * Start a timer for the given key, and guards that this is the first time this key is started.
     * Call {@link IStoppableStopwatch#stop} on the returned stopwatch to stop the timer.
     */
    start(key: T): IStoppableStopwatch;
    /**
     * Automatically call {@link Measurements#start | start} and the corresponding stop to measure the execution time of the given function.
     * @see {@link measureAsync}
     */
    measure<Out>(key: T, fn: () => Out): Out;
    /**
     * Similar to {@link measure}, but await the promise as part of the measurement
     * @param key - The key to write the resulting measurement to
     * @param fn  - The function to measure
     * @see measure
     */
    measureAsync<Out>(key: T, fn: () => Promise<Out>): Promise<Out>;
    /**
     * Retrieve all measure-results, requires that all stop-watches that have been started have also been stopped.
     */
    get(): Map<T, bigint>;
}