// TODO: Test
/// <summary>
/// Shuffles the items in the list according to the specified random source.
/// </summary>
/// <param name="list">The list to shuffle.</param>
/// <param name="random">The random source.</param>
public static void Shuffle <T>(this SCG.IList <T> list, Random random)
{
#region Code Contracts
// Argument must be non-null
Requires(list != null, ArgumentMustBeNonNull);
// List must be non-read-only
Requires(!list.IsReadOnly, CollectionMustBeNonReadOnly);
// The elements are the same
Ensures(list.HasSameAs(OldValue(list.ToList())));
#endregion
if (random == null)
{
random = new Random(); // TODO: Use C5.Random?
}
var n = list.Count;
while (--n > 0)
{
list.Swap(random.Next(n + 1), n);
}
}