public static IEnumerable <T> ThenBy <T, U>(this OrderedSequence <T> seq, Func <T, U> criterium)
where U : IComparable <U>
{
var a = seq.Elements.ToArray();
var c = seq.Comparer;
Array.Sort(a, (t1, t2) => c(t1, t2) + criterium(t1).CompareTo(criterium(t2)));
return(a);
}
public static IEnumerable <T> OrderBy <T, U>(this IEnumerable <T> seq, Func <T, U> criterium)
where U : IComparable <U>
{
OrderedSequence <T> sequence = new OrderedSequence <T>((t1, t2) => criterium(t1).CompareTo(criterium(t2)), seq);
return(sequence);
//var a = seq.ToArray();
//Array.Sort(a, (t1, t2) => criterium(t1).CompareTo(criterium(t2)));
//return a;
}