Generic List - moving an item within the list

Question

So I have a generic list, and an oldIndex and a newIndex value.

I want to move the item at oldIndex, to newIndex.

Answer 1

This is how I implemented a move element extension method. It handles moving before/after and to the extremes for elements pretty well.

public static void MoveElement(this IList list, int fromIndex, int toIndex)
{
  if (!fromIndex.InRange(0, list.Count - 1))
  {
    throw new ArgumentException("From index is invalid");
  }
  if (!toIndex.InRange(0, list.Count - 1))
  {
    throw new ArgumentException("To index is invalid");
  }

  if (fromIndex == toIndex) return;

  var element = list[fromIndex];

  if (fromIndex > toIndex)
  {
    list.RemoveAt(fromIndex);
    list.Insert(toIndex, element);
  }
  else
  {
    list.Insert(toIndex + 1, element);
    list.RemoveAt(fromIndex);
  }
}