Re: Object with zero bits

[Nick Roberts <nick.roberts@acm.org>]

Georg Bauhaus wrote:

> : But many (perhaps most) compilers will make an object (or component) of
> : type (subtype) Nothing_At_All at least size 1 (one bit).
> 
> An object of type Nothing_At_All can be 8 bits in size.
> But Nothing_At_All as a record component seems to vanish,
> 
>   type Num is limited record
>      virt: Nothing_At_All := initialize_Num(Num'access);
>      n: Natural;
>   end record;
> 
>   pragma assert(Num'Max_Size_in_Storage_Elements = 4);
> 
> With suitable rep clauses, Boolean discriminants don't seem to consume
> space in some variant records, when the compiler can find out :-)

Which compiler please?  Would you be kind enough to post test code.

-- 
Nick Roberts