export declare function tail(arr: T[]): [T[], T]; export declare function last(arr: T[]): T | undefined; export declare function sequenceEquals(arr1: T[], arr2: T[]): boolean; /** * Pushes an element to the start of the array, if found. */ export declare function pushToStart(arr: T[], value: T): void; /** * Pushes an element to the end of the array, if found. */ export declare function pushToEnd(arr: T[], value: T): void; export declare function firstIndex(array: T[] | ReadonlyArray, fn: (item: T) => boolean): number; export declare function remove(array: T[], value: T): boolean;