ducktypes_disposablle.cs

ducktypes_disposablle.cs

using System;
using System.Collections.Generic;

namespace ConsoleApp1
{
    public class CustomEnumerable
    {
        public class CustomEnumerator : IDisposable
        {
            private readonly CustomEnumerable _enumerable;
            private int _index = -1;
            public CustomEnumerator(CustomEnumerable enumerable) => _enumerable = enumerable;
            private IList<string> Items => _enumerable._items;
            public string Current => _index >= 0 ? Items[_index] : null;

            public bool MoveNext()
            {
                if (_index >= Items.Count - 1) return false;
                _index++;
                return true;
            }

            public void Dispose()
            {
                Console.WriteLine("Disposed");
            }
        }

        private readonly IList<string> _items;
        public CustomEnumerable(params string[] items) => _items = new List<string>(items);
        public CustomEnumerator GetEnumerator() => new CustomEnumerator(this);
    }

    public class C
    {
        public static void Main()
        {
            var enumerable = new CustomEnumerable("One", "Two", "Three");

            foreach (string item in enumerable)
            {
                Console.WriteLine(item);
            }
        }
    }
}