Ada subtypes and base types

[Jeffrey A Law]

On Sat, 2006-02-25 at 09:48 +0100, Zdenek Dvorak wrote:
> Hello,
> 
> > Jeffrey A Law wrote:
> > > Another possibility is to simply not allow conversions between a
> > > subtype and basetype. 
> > 
> > Such a patch also solves the problem.  But I'm not sure to understand
> > the impact on other codes.  Is this kind of conversion between a type
> > and its basetype specific to Ada?
> 
> this still seems unnecessarily conservative to me.  I would just check
> for types whose TYPE_MIN and TYPE_MAX do not match the natural values
> derived from the type precision (i.e., those returned by
> upper_bound_in_type (type, type) and lower_bound_in_type (type, type)).
I doubt it matters in any significant way -- your proposed solution
may allow optimization in a few more cases of Ada code, but at a 
compile-time cost (probably not significant).

Either approach is OK with me.    I'll probably get one spun completely
today which will hopefully get Ada building again.

jeff