/**
 * Represents a bit set, which is a collection of bits that can be individually set or queried.
 */
export declare class BitSet {
    readonly n: bigint;
    /**
     * Creates a new instance of the BitSet class.
     *
     * @param n - BitSet represented as `bigint`.
     */
    private constructor();
    /**
     * Creates an empty BitSet instance.
     *
     * @returns A new empty BitSet instance.
     */
    static empty(): BitSet;
    /**
     * Returns a bit the specified `index` as a boolean value. 0 = `false`, 1 = `false`.
     *
     * @param index - The index of the value to retrieve. Must be a non-negative integer.
     * @returns The boolean value at the specified index. Returns false if the index referenced is not set yet.
     */
    at(index: number): boolean;
    /**
     * Sets the value of the bit at the given index in the BitSet.
     *
     * @param index - The index of the bit to set.
     * @param value - The value to set the bit to.
     * @return A new BitSet with the bit at the given index set to the specified value.
     */
    set(index: number, value: boolean): BitSet;
    /**
     * Presents bitset as a bigint.
     */
    toBigInt(): bigint;
}