Lifo.cs

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

namespace Hyper.PCAAprilTag
{
    /// <summary>
    /// LIFO (Last-In-First-Out) List
    /// </summary>
    /// <typeparam name="T"></typeparam>
    public class Lifo<T>
    {
        private readonly int _capacity;
        private readonly List<T> _list;

        public Lifo(int capacity)
        {
            _capacity = capacity;
            _list = new List<T>(capacity);
        }

        public void Push(T item)
        {
            if (_list.Count >= _capacity)
            {
                _list.RemoveAt(0);
            }

            _list.Add(item);
        }

        public T Pop()
        {
            if (_list.Count == 0) return default;

            var item = _list[0];
            _list.RemoveAt(0);
            return item;
        }

        public T Top => _list.Last();

        public T this[int index] => _list[index];

        public bool IsEmpty => _list.Count == 0;

        public bool IsFull => _list.Count >= _capacity;

        public int Count => _list.Count;

        public List<T> ToList() => new List<T>(_list);
    }
}