Type C # 3.0 Func / OrderBy Output

Question

So the weird situation I came across today with OrderBy:

Func<SomeClass, int> orderByNumber = 
  currentClass => 
   currentClass.SomeNumber;

Then:

someCollection.OrderBy(orderByNumber);

This is good, but I was going to create a method instead, because it can be used elsewhere than orderBy.

private int ReturnNumber(SomeClass currentClass)
{
  return currentClass.SomeNumber;
}

Now when I try to connect it to OrderBy:

someCollection.OrderBy(ReturnNumber);

He cannot infer a type like him if I use Func. It seems to me that they should be the same, since the method itself is "strongly typed", like Func.

Side Note: I understand that I can do this:

Func<SomeClass, int> orderByNumber = ReturnNumber;

Answer 1

This may also be due to a "return type type inference" that does not work in method groups .

, (, Where), , . , (, Select OrderBy), .

Answer 2

ReturnNumber - , ReturnNumber, arity-. , . , , , , , , .

:

someCollection.OrderBy(new Func<SomeClass, int>(ReturnNumber))