Re: Standard missing a 'Negative' subtype?...

[Shark8 <onewingedshark@gmail.com>]

On Saturday, September 14, 2013 2:49:08 AM UTC-6, Martin wrote:
> Why is there no "Negative" predefined subtype in package Standard?...

Because you don't often need strictly negative numbers... but if you do you could use the following Ada 2012 construct:

    subtype Negative is Integer
    with Static_Predicate => Negative not in Natural;

Or the more traditional Ada83 Range:

    subtype Negative is Integer is range
         Integer'First..Integer'Pred(Natural'First); -- or Integer'First..-1.

(I like using use Integer/Natural/Positive attributes when defining things in terms of subtypes because it avoids hardcoded-constants and makes the type/sybtype relations obvious: the definition becomes stated in terms of it's "type-class".)