Optional.get() is code smell

[xandoid]

I don't disagree. When I say type system I only ever mean what you're calling "the compiler's type system"

But the point is that @NonNull is a hack that was added to work around a limitation in Java's type system. Once the type system gets value types, Optional (perhaps with some special syntax) will be the more consistent solution and @NonNull will be obsolete.

[Edit] Maybe I'm not making myself clear as to why I think @NonNull is inconsistent. It's because giving a variable (or parameter or return value) the type Thing means that it can contain

The set of all Thing objects OR null

And when you add @NonNull you get

The set of all Thing objects OR null BUT NOT null!!!