Re: Enumeration representation clause surprise.

[Mike Silva <snarflemike@yahoo.com>]

On Jun 12, 2:41 pm, Markus Schöpflin <nos...@nospam.org> wrote:
> Mike Silva schrieb:
>
> > On Jun 12, 4:45 am, Markus Schoepflin <nos...@no.spam> wrote:
> >> Both GNAT and Dec Ada return 1 and 2 for both A1 and A2, so they are
> >> correctly debiasing when explicitly asked for the internal representation.
>
> >> Markus
>
> > Now I'm really confused.  In your OP you showed some "incorrect"
> > binary values - how did you get those values?  By inspecting memory?
>
> Yes.
>
> > Now you talk about explicitly asking for the internal representation.
> > What does that mean exactly?
>
> Using unchecked conversion to ask for the value of the variables.
>
> > Are you saying now that there's no problem after all?
>
> Not at all. The memory layout of the variables is not what I expect it
> to be, because the compiler silently biased those values. The compiler
> is perfectly aware of this, as it makes up for the biasing when
> explicitly querying the value, but this doesn't help at all because I'm
> interested in the exact bitwise representation.
>
> Admittedly, there is an inconsistency in what I'm asking the compiler to
> do, but that's the whole point: I do not want this inconsistency to be
> silently 'fixed' by the compiler, I want to get noted about my error to
> get a chance and fix it myself.

I wonder then if this is an error at all.  IANALL, but if the program
makes available your specified values when queried with the proper
mechanism (in this case, unchecked conversion), then I don't see what
difference it makes how it stores the representations in raw memory.

I'd welcome other comments on the validity or non-validity of this
view.

Mike