/**
 * A collection of static array utility functions.
 */
export default class ArrayPoly {
    /**
     * Filter elements in an array to only unique values, using the result of a mapper function to
     * test for equality. Usage:
     *
     * <code>
     * ['a', 'b', 'c', 'a', 'A', 'C'].filter(ArrayPoly.filterUniqueMapped((str) => str.toUpperCase());
     * </code>
     */
    static filterUniqueMapped<T>(mapper: (arg: T) => unknown): (value: T, idx: number, values: T[]) => boolean;
    /**
     * Reduce elements in an array to chunks of size {@link limit}.
     *
     * <code>
     * [1, 2, 3, 4, 5, 6, 7, 8, 9, 10].reduce(ArrayPoly.reduceChunk(3), []);
     * </code>
     */
    static reduceChunk<T>(limit: number): (previous: T[][], current: T, idx: number, array: T[]) => T[][];
    /**
     * Reduce elements in an array to only unique values. Usage:
     *
     * <code>
     * [1, 2, 3, 1, 1, 3].reduce(ArrayPoly.reduceUnique(), []);
     * </code>
     */
    static reduceUnique<T>(): (previous: T[], current: T, idx: number, array: T[]) => T[];
}