import type { CompareFunction } from "../types/array/compareFunction";
/**
 * Merge sort implementation
 * @param  {T[]} array Array to sort
 * @param  {(a: T, b: T) => number} compareFunction Comparison function
 * @returns {T[]} Sorted array
 * @example mergeSort([1, 3, 2, 4, 5], (a, b) => a - b); // [1, 2, 3, 4, 5]
 */
export declare const mergeSort: <T>(array: T[], compareFunction?: CompareFunction<T>) => T[];