Method removeFirst

data_structures/deque.ts:331–335

* Remove and return the first element matching the predicate, scanning from * front to back. The gap is closed by shifting whichever side (front or back) * has fewer elements to move, so removals near either end are fast. * * @example Removing the first even number * ```ts * import

(predicate: (value: T, index: number) => boolean)

   * @returns The removed element, or `undefined` if no match was found.
   */
  removeFirst(predicate: (value: T, index: number) => boolean): T | undefined {
    const i = this.#findIndex(predicate);
    if (i === -1) return undefined;
    return this.#removeAtUnchecked(i);
  }

  /**
   * Remove and return the element at the given index (0-based from front).