/**
 * Utility namespace used by the sorted B‑tree implementations to encode
 * positions within a node.<br/>
 * <br/>
 * Non‑negative values represent entry indices, while negative values
 * represent child positions encoded using {@link SortedIndex.firstChild}
 * and the {@link SortedIndex.next} / {@link SortedIndex.prev} helpers.
 */
export declare namespace SortedIndex {
    /**
     * Returns the next encoded index after the given `index`.<br/>
     * <br/>
     * The sequence walks over both entries and children inside a node in
     * a consistent order and is used to traverse node contents.
     * @param index - the current encoded index
     */
    function next(index: number): number;
    /**
     * Returns the previous encoded index before the given `index`.<br/>
     * <br/>
     * Together with {@link SortedIndex.next} this allows iteration in
     * both directions over entries and children within a node.
     * @param index - the current encoded index
     */
    function prev(index: number): number;
    /**
     * Encoded index representing the position of the first child inside a node.
     * Used as a starting point when traversing children with
     * {@link SortedIndex.next} / {@link SortedIndex.prev}.
     */
    const firstChild = -1;
    /**
     * Compares two encoded indices and returns a negative number if `i1` comes
     * before `i2`, a positive number if `i1` comes after `i2`, or `0` when
     * they represent the same position.
     * @param i1 - the first encoded index
     * @param i2 - the second encoded index
     */
    function compare(i1: number, i2: number): number;
}