export declare function addItem<T>(array: T[], item: T): T[];
export declare function removeItem<T>(array: T[], item: T): T[];
export declare function findItem<T>(array: T[], item: T): T | undefined;
export declare function removeIndex<T>(array: T[], index: number): T[];
export declare function getFirstItem<T>(array: T[]): T | undefined;
export declare function getLastItem<T>(array: T[]): T | undefined;
export declare function distinct<T>(array: T[]): T[];