Re: Representation clause for enumeratives

["Ken Garlington" <Ken.Garlington@computer.org>]

As an aside, here's some fun you can have with the following package in GNAT
3.12p:

: package Big_Enum is
:
:    type Object is  (A, B, C);
:
:    for Object use(
:       16#0000_0002#,
:       16#0000_0004#,
:       16#8000_0000#
:       );
:
:    for Object'Size use 32;
:
: end Big_Enum;

-- This works:

   for Object use(
      16#0000_0000#,
      16#7FFF_FFFF#,
      16#8000_0000#
      );

-- But change it to the following, and you get "value not in range of type
'Standard.Integer'"
-- (I only changed the first value to -1; it's not in Standard.Integer? :)

   for Object use(
      -1,
      16#7FFF_FFFF#,
      16#8000_0000#
      );

-- This works fine....

   for Object use(
      1,
      2,
      16#FFFF_FFFF#
      );

-- But the following draws the Standard.Integer message...

   for Object use(
      -16#FFFF_FFFF#,
      -2,
      -1
      );

Tsk - these limited enumeration representation ranges... :)

I wouldn't mind this behavior in a numeric type...

type Hardware_Numeric is range (-16#8000# .. 16#7FFF#) or ( 16#0000# ..
16#FFFF#);

A : Hardware_Numeric := -1; -- all further literals must be in range of
first clause...
X : Hardware_Numeric := 16#8000#; -- all further literals must be in range
of second clause...

Get that into Ada 0Y for me, will ya? :)