Re: GNAT GPL 2009 - issue with floating points?

[Adam Beneschan <adam@irvine.com>]

On Oct 9, 1:36 pm, Damien Carbonne <damien.carbo...@free.fr> wrote:
> Hi,
>
> When compiling the following sample code with GNAT GPL 2009 on Linux:
>
> generic
>     type Real is digits <>;
> package Pack04 is
>     Size1 : constant := Real'Size;
>     Size2 : constant Integer := Real'Size;
> end Pack04;
>
> I get this:
>
> -- pack04.ads:4:24: non-static expression used in number declaration
> -- pack04.ads:4:28: size attribute is only static for scalar type (RM
> 4.9(7,8))
>
> RM 3.5(1): "scalar types comprise enumeration types, integer types, and
> real types."
>
> RM 3.5.6 (1): "Real types provide approximations to the real numbers,
> with relative bounds on errors for floating point types, and with
> absolute bounds for fixed point types."

Did you read the RM reference that the GNAT error message pointed you
to???

Also read 4.9(26).

> So Real is supposed to be a scalar!
>
> Is this a problem with (misleading) message or with (effectively) wrong
> code?

The code is wrong.

And anyway, the declaration of Size2 is legal (even though the
declaration of Size1 isn't), so there's no problem.

                             -- Adam