//fast path, that implementation detail does not really need to be API
private static Array ArrayFromCollection(Type elementType, ICollection collection)
{
if (null == elementType)
{
throw new ArgumentNullException("elementType");
}
if (null == collection)
{
throw new ArgumentNullException("collection");
}
Array array = Array.CreateInstance(elementType, collection.Count);
if (RuntimeServices.IsPromotableNumeric(Type.GetTypeCode(elementType)))
{
int i = 0;
foreach (object item in collection)
{
object value = RuntimeServices.CheckNumericPromotion(item).ToType(elementType, null);
array.SetValue(value, i);
++i;
}
}
else
{
collection.CopyTo(array, 0);
}
return(array);
}
public static Array array(Type elementType, IEnumerable enumerable)
{
if (null == elementType)
{
throw new ArgumentNullException("elementType");
}
if (null == enumerable)
{
throw new ArgumentNullException("enumerable");
}
#pragma warning disable 618 //obsolete
ICollection collection = enumerable as ICollection;
if (null != collection) //fast path
{
return(ArrayFromCollection(elementType, collection));
}
#pragma warning restore 618
List l = null;
if (RuntimeServices.IsPromotableNumeric(Type.GetTypeCode(elementType)))
{
l = new List();
foreach (object item in enumerable)
{
object value = RuntimeServices.CheckNumericPromotion(item).ToType(elementType, null);
l.Add(value);
}
}
else
{
l = new List(enumerable);
}
return(l.ToArray(elementType));
}
public static Array array(Type elementType, IEnumerable enumerable)
{
if (null == enumerable)
{
throw new ArgumentNullException("enumerable");
}
if (null == elementType)
{
throw new ArgumentNullException("elementType");
}
// future optimization, check EnumeratorItemType of enumerable
// and get the fast path whenever possible
List l = null;
if (RuntimeServices.IsPromotableNumeric(Type.GetTypeCode(elementType)))
{
l = new List();
foreach (object item in enumerable)
{
object value = RuntimeServices.CheckNumericPromotion(item).ToType(elementType, null);
l.Add(value);
}
}
else
{
l = new List(enumerable);
}
return(l.ToArray(elementType));
}