scoping invariants

[Jarrett Billingsley]

On Mon, Mar 16, 2009 at 1:50 PM, Nicholas Jordan <asdf at some.com> wrote:
> 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.

The problem is that this conflicts with the D1 syntax for class/struct
invariants.  This is probably why the immutable keyword has been
introduced, and I have a feeling invariant as a form of constness will
be renamed immutable.

Just use:

immutable
{
    long foo = 4;
    int bar = 12;
}

But you said that these are return statuses?  Why not use enums instead?