using System.Collections.Generic; using System.Linq; namespace DarkUI.Extensions { internal static class IEnumerableExtensions { internal static bool IsLast(this IEnumerable items, T item) { var last = items.LastOrDefault(); if (last == null) return false; return item.Equals(last); } internal static bool IsFirst(this IEnumerable items, T item) { var first = items.FirstOrDefault(); if (first == null) return false; return item.Equals(first); } internal static bool IsFirstOrLast(this IEnumerable items, T item) { return items.IsFirst(item) || items.IsLast(item); } } }