Re: Pragma for conditional compilation? (Ada 2005 vs. 95)

[Jerry <lanceboyle@qwest.net>]

On Sep 27, 8:26 am, a...@anon.org (anon) wrote:

Thanks, anon, for the detailed answer.

>
> The third real old way is to code in the option by a "IF-THEN-ELSE-END"
> statements and use a Global constant variable(s). Its low tech but it
> still works.

OK, but my "problem" is in declaring types which I want to be visible
in 95 but not visible in 05, as 05 provides them itself. An "IF-THEN-
ELSE-END" solution would have to be in the executable part of the
program (right?).


> The fifth is a "NON STANDARD" way that GNAT introduce with the
> pre-release of Ada_2005 which is to use the "pragma Ada_05 ( name ) ;"
>
> Example:
>
> -- For GNAT you can create a routine that is define and is usable
> -- only in Ada_2005 specs, by using the GNAT pragma Ada_05.
> --
> -- Gnat uses this concept in the  Ada.Text_IO package. Just
> -- search for "Ada_05" in the file "a-textio.ads". There are
> -- two Get_Line functions. If the system is compiled with
> -- "pragma Ada_83 ;" or "pragma Ada_95" the compile will not
> -- allow a call to these routines. But under Ada_05 the routine is
> -- visible.
> --
> -- Defined in the specification file.
>
>    procedure Routine ;
>    pragma Ada_05 ( Routine ) ;
>
> --
> -- Defined in the body file.
> --
>    procedure Routine is
>      begin -- Routine
>         null ;
>      end Routine ;
>
Same comment as above--how would this work for type declarations?
Could I follow the type declaration with the pragma? Also, I need to
conditionally have a with clause. For example, if using Ada 2005, I
need a line like this:

  with Ada.Numerics.Long_Real_Arrays;
  use  Ada.Numerics.Long_Real_Arrays;

(This is where the vector and matrix declarations are.)

Jerry