What problem does IStructuralEquatable and IStructuralComparable solve?

Question

I\'ve noticed these two interfaces, and several associated classes, have been added in .NET 4. They seem a bit superfluous to me; I\'ve read several blogs about them, but I

Answer 1

The description of the IStructuralEquatable Interface says (in the "Remarks" section):

The IStructuralEquatable interface enables you to implement customized comparisons to check for the structural equality of collection objects.

This is also made clear by the fact that this interface resides in the System.Collections namespace.