using System.Collections.Generic; namespace System.Collections.ObjectModel { internal static class CollectionHelpers { internal static void ValidateCopyToArguments(int sourceCount, Array array, int index) { if (array == null) throw new ArgumentNullException("array"); if (array.Rank != 1) throw new ArgumentException(System.SR.Arg_RankMultiDimNotSupported, "array"); if (array.GetLowerBound(0) != 0) throw new ArgumentException(System.SR.Arg_NonZeroLowerBound, "array"); if (index < 0 || index > array.Length) throw new ArgumentOutOfRangeException("index"); if (array.Length - index < sourceCount) throw new ArgumentException(System.SR.Arg_ArrayPlusOffTooSmall); } internal static void CopyTo<T>(ICollection<T> collection, Array array, int index) { ValidateCopyToArguments(collection.Count, array, index); ICollection collection2 = collection as ICollection; if (collection2 != null) collection2.CopyTo(array, index); else { T[] array2 = array as T[]; if (array2 != null) collection.CopyTo(array2, index); else { object[] array3 = array as object[]; if (array3 == null) throw new ArgumentException(System.SR.Argument_IncompatibleArrayType, "array"); try { foreach (T item in (IEnumerable<T>)collection) { array3[index++] = item; } } catch (ArrayTypeMismatchException) { throw new ArgumentException(System.SR.Argument_IncompatibleArrayType, "array"); } } } } } }