c# 泛型和索引

class YList<T>
    {
        private T[] _list;

        public YList(T[] ts){
            _list = ts;
        }

        public YList() { 
            _list = new T[5];
        }
        public T this[int i] {
            get
            {
                return _list[i];
            }
            set {
                _list[i] = value;
            }
        }
    }