Listをデフォルト値で初期化する

DefaultInitCollection.cs

using System;
using System.Collections;
using System.Collections.Generic;

List<int> list = new List<int>(new DefaultInitCollection(10));

foreach (var e in list)
{
    Console.WriteLine(e);
}

class DefaultInitCollection : ICollection<int>
{
    int _size = 0;
    public DefaultInitCollection(int size) => _size = size;

    public int Count => _size;

    public void CopyTo(int[] array, int arrayIndex)
    {
        // 何もしない
    }

    public bool IsReadOnly => true;
    public void Add(int item) {}
    public void Clear() {}
    public bool Contains(int item) => false;
    public IEnumerator<int> GetEnumerator() => null;
    public bool Remove(int item) => false;
    IEnumerator IEnumerable.GetEnumerator() => null;
}