Re: Ada Alternatives to Unrestricted_Access

[Jere <jhb.chat@gmail.com>]

On Friday, March 9, 2018 at 11:46:03 AM UTC-5, Jeffrey R. Carter wrote:
> On 03/09/2018 01:36 AM, Jere wrote:
> > 
> > It generates the error "access-to-variable designates constant" because
> > the function takes a parameter of mode "in" while the iterator needs
> > a non-constant access to the variable.  I can't change the mode of the
> > function for other reasons.
> 
> OK, that's what I missed. I guess you could unchecked convert from 
> access-constant to access-all.
> 
My only concern with this is does the Ada language allow it portably?  I
know it works in GNAT, but what I couldn't find is if the RM allowed
for a constant variable to have a different internal representation than
a non constant version of the variable.  If that were the case, then I 
would be worried that doing an unchecked_conversion (or an
Address_To_Access_Conversion) could provide an erroneous result.

I've been dipping into the RM but haven't found what I am looking for yet.