scoping invariants

[Nicholas Jordan]

I put some fields at the front of my first attempt as a note while
prototyping, the compiler did not accept the syntax from the sample
code. I had to do it like this:

invariant {long fail__= -123456;}

with the brackets surrounding, for this question - what I want here is
several values that are never changeable and always represent some
sort of status return from calls - always the same. The above code is
not compliant with the code shown in the discussion of what D is all
about.

Narrowly, is the above code stable for use in other scopes?