Re: 'Base

[Martin Dowie <martin.dowie@btopenworld.com>]

Matthew Heaney wrote:
> Martin Dowie wrote:
> 
>>Sorry Matt - you must be ill or something as you're a wee bit "off base"
>>with your answer to this one!
> 
> [snip]
> 
>>It isn't -42 .. 42 but the 'First .. 'Last or the underlying integer
>>representation. In this case (with ObjectAda) -2147483648 to 2147483647.
> 
> 
> 
> I should have said that T'Base'Last is *at least* T'Last, of course it
> can be larger.
> 
> However, this doesn't undermine the my point that you can only depend
> on having the range guanteed by the RM, in this case -42 .. 42.
> 
> So yes it's true that your base type might include all of the values in
> a 32 bit range, but that fact is irrelevant.  The range specified in
> the RM is the only range that matters.

I just don't see that from RM 3.5, esp para 6 - and I've been back to 
Cohen and I can't see that from page 183. I'm no Language Lawer, so 
could you please point this range guarantee out to me in the RM?

I'm having trouble seeing how your definition meets the " it is also the 
range supported at a minimum for intermediate values during the 
evaluation of expressions involving predefined operators of the type." bit.

Cheers

-- Martin