/****
 *
 * separates an single array into an array of successes and an array of fails
 * success is based on the truthiness of an predicate function
 *
 * successes are the first value of the return tuple
 *****/
export declare function filterAndSeparate<TItem>(items: TItem[], predicate: (item: TItem) => boolean): readonly [TItem[], TItem[]];
export declare function findDuplicates<TItem>(items: TItem[]): TItem[];