export interface CalculateVisibleCountParams {
    /** Width of each item in source order (px). */
    itemWidths: number[];
    /** Gap between flex children of the container (px). */
    gap: number;
    /** Available width of the container (px). */
    availableWidth: number;
    /** Measured width of the '+N' indicator (px); fallback — reserveSpace. */
    indicatorWidth: number;
}
/**
 * Pure arithmetic: how many leading items fit before an overflow indicator
 * is required. Does not touch the DOM — safe to call on every resize frame.
 */
export declare function calculateVisibleCount({ itemWidths, gap, availableWidth, indicatorWidth, }: CalculateVisibleCountParams): number;