Prefer == null and != null over HasValue with Nullable<T>

[amanda-mitchell]

I could easily be persuaded to go the other way on this one, but the point is that we should have exactly one way of doing it.

[ddunkin]

+1 for comparison to null.

[ejball]

I also prefer comparison with null.

It feels a little strange, since I also prefer Value to a C-style cast.

int? number = TryGetNumber();
if (number != null) // vs. number.HasValue
    SetNumber(number.Value); // vs. (int) number

But I'm really hoping that they will eventually support ! on Nullable<T> values. (If there's an issue for that, I can't find it.)

int? number = TryGetNumber();
if (number != null)
    SetNumber(number!);

[amanda-mitchell]

It feels a little strange, since I also prefer Value to a C-style cast.

I started to also create an issue to require Value instead of C-style casts, but the internal inconsistency bothered me enough that I stopped short of doing so.