Question

Enumerable.Sum() is only defined for IEnumerable where T in

double,
double?
int,
int?
decimal,
decimal?
long,
long?
float,
float?

Is there a reason for not defining for byte, short or uint?

1. Is it to avoid overflow problems?
2. Or does it make type inference difficult for compiler? (Most Likely)

Answer 1

Because when you add a short and a short the outcome can be handled by an int.
Could be some CLS compliant issues as well. This was posted as a similiar question:

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