public static void AddLast <T>([NotNull] this IList <T> list, [NotNull] T item) { if (list.IsReadOnly) { ExceptionThrower.ThrowArgumentReadOnlyCollectionException(nameof(list)); } list.Insert(list.Count, item); }
/// <summary> /// Adds if not exists. /// </summary> /// <typeparam name="T">Generic type parameter.</typeparam> /// <param name="list">The list.</param> /// <param name="item">The value.</param> /// <returns><c>true</c> if XXXX, <c>false</c> otherwise.</returns> /// <exception cref="ArgumentNullException">list - List cannot be null. or value - Value cannot be null.</exception> /// <exception cref="ArgumentException">list - List cannot be null. or value - Value cannot be null.</exception> /// <exception cref="ArgumentNullException">list - List cannot be read-only.</exception> /// <exception cref="ArgumentException">list - List cannot be null. or value - Value cannot be null.</exception> public static bool AddIfNotExists <T>([NotNull] this ICollection <T> list, [NotNull] T item) { if (list.IsReadOnly) { ExceptionThrower.ThrowArgumentReadOnlyCollectionException(nameof(list)); } if (list.Contains(item)) { return(false); } list.Add(item); return(true); }