LINQ Optimizations for IOrderedEnumerable

Question

Is anyone aware of whether there are there any built-in capabilities in the LINQ library (or a publicly available utility library) for optimized operations on IOrderedEnumerable<T>, as opposed to IEnumerable<T>?

For example, in theory, the Contains<T>() extension could potentially be optimized to use binary search when it is applied to a finite IOrderedEnumerable<T> and T is IComparable.

Another example, would be an optimized version of Distinct<T>() that would be deferred and streamable (since on an ordered, comparable collection you can always use skip/match techniques to produce a distinct set).

Answer 1

There are problems there...

• A binary search can't be executed on an IOrderedEnumerable<T>, as it ideally needs indexer access into a list/array. So it would have to call something like ToList()/ToArray() first
• Distinct works on the T items, but OrderBy works on some facet of each T - it isn't quite the same, unless you happen to know that it is ordered by item=>item; which is rarely the case (and hard to prove).