Re: In case statment? (was Re: is exception when others => null; smart?)

[prichtmyer@yahoo.com (Peter Richtmyer)]

Lutz Donnerhacke <lutz@iks-jena.de> wrote in message news:<slrnarv9vv.pr.lutz@taranis.iks-jena.de>...
> * Peter Richtmyer wrote:
> > As the following example illustrates, it really depends upon
> > the compiler too. A "bad" value is handled differently as
> > shown:
> > -----------------------------------------------------------
> > with system;
> > with text_io;
> > procedure test is
> >     
> >      a : character := character'val(2#11111111#);   
> >      for a'size use 8;
> >      b : boolean;
> >      for b'address use a'address;
> >      for b'size use 8;
> 
> Don't map variable b without pragma Import(Ada, b);
> This prevents initialising of address space, which--in this case--renders
> your example unusable.

The type boolean does not have a default value, so the program 
behaves the same (on Gnat) with or wothout the Pragma. You can see 
this by adding this line after "begin":

   text_io.put_line ("a'pos is " & integer'image (character'pos(a)));

and you should see:    a'pos is  255

Mapping the 'b' variable over 'a' does not affect the value of 'a' here.

Peter