declare class Denque<T = any> {
  length: number;

  constructor();

  constructor(array: T[]);

  constructor(array: T[], options: IDenqueOptions);

  push(item: T): number;

  unshift(item: T): number;

  pop(): T | undefined;

  shift(): T | undefined;

  peekBack(): T | undefined;

  peekFront(): T | undefined;

  peekAt(index: number): T | undefined;

  get(index: number): T | undefined;

  remove(index: number, count: number): T[];

  removeOne(index: number): T | undefined;

  splice(index: number, count: number, ...item: T[]): T[] | undefined;

  isEmpty(): boolean;

  clear(): void;

  size(): number;

  toString(): string;

  toArray(): T[];
}

interface IDenqueOptions {
  capacity?: number
}

export = Denque;