Why is there no Sum() extension for IEnumerable<uint>

Question

It seems that Sum is not defined for IEnumerable<uint> (and other unsigned integers, for that matter)

var s = new int[] { 1, 2, 3 };
s.Sum(); //works fine

var us = new uint[] { 1, 2, 3 };
us.Sum(); //missing method

I would like to know:

• Have I done something fundamentally wrong/misunderstood the situation?
• What design decisions might cause the omission of IEnumerable<uint>.Sum()?

MSDN: Enumerable.Sum

Answer 1

Just a guess: Because uint is not CLS-compliant. Not sure if that would weigh in their decision to not support it.