pub const IteratorOptions = struct {
    /// determines which bits should be visited
    kind: Type = .set,
    /// determines the order in which bit indices should be visited
    direction: Direction = .forward,

    pub const Type = enum {
        /// visit indexes of set bits
        set,
        /// visit indexes of unset bits
        unset,
    };

    pub const Direction = enum {
        /// visit indices in ascending order
        forward,
        /// visit indices in descending order.
        /// Note that this may be slightly more expensive than forward iteration.
        reverse,
    };
}