C# foreach를 사용할 수 있는 일반화 클래스 예제 구현

class MyList<T> : IEnumerable<T>, IEnumerator<T> {
    T[] array;
    int position = -1;

    public MyList() {
        array = new T[3];
    }

    public T this[int index] {
        get {
            return array[index];
        }
        set {
            if(index >= array.Length) {
                Array.Resize<T>(ref array, index + 1);
                Console.WriteLine($"Array Resized : {array.Length}");
            }

            array[index] = value;
        }
    }

    public int Length {
        get { return array.Length; }
    }

    public IEnumerator<T> GetEnumerator() {
        for (int i = 0; i < array.Length; i++) {
            yield return (array[i]);
        }
    }

    IEnumerator IEnumerable.GetEnumerator() {
        for (int i = 0; i < array.Length; i++) {
            yield return (array[i]);
        }
    }

    public T Current {
        get { return array[position]; }
    }

    object IEnumerator.Current {
        get { return array[position]; }
    }

    public bool MoveNext() {
        if(position == array.Length - 1) {
            Reset();
            return false;
        }

        position++;
        return (position < array.Length);
    }

    public void Reset() {
        position = -1;
    }

    public void Dispose() {

    }
}

class MainApp {
    static void Main(string[] args) {
        MyList<int> int_list = new MyList<int>();
        int_list[0] = 10;
        int_list[1] = 20;
        int_list[2] = 30;
        int_list[3] = 40;
        int_list[4] = 50;

        foreach (var item in int_list) {
            Console.WriteLine(item);
        }
    }
}

 

 

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