Re: Generalized serialization for enumeration types

[okellogg <okellogg@freenet.de>]

On 26 Aug., 13:33, xorque <xorquew...@googlemail.com> wrote:
> On Aug 26, 11:00 am, okellogg <okell...@freenet.de> wrote:
>
> > If your enums are represented as you describe then why do you need
> > representations?
> > You could rely on the natural Ada representation (which happens to
> > conform with your encoding rules as far as the enum values are
> > concerned).
>
> Erm. Where in the (2005) RM does it state that enums are encoded
> at big-endian 32 bit integers?
>

Perhaps I am misunderstanding - I thought along following lines:

-- file: enum_to_big_endian_unsigned32.ads
with Interfaces;
generic
   type Enum_Type is (<>);
function Enum_To_Big_Endian_Unsigned32 (Value : Enum_Type)
         return Interfaces.Unsigned_32;

-- file: enum_to_big_endian_unsigned32.adb
function Enum_To_Big_Endian_Unsigned32 (Value : Enum_Type)
         return Interfaces.Unsigned_32 is
   function htonl (host_int : Interfaces.Unsigned_32)
                   return Interfaces.Unsigned_32;
   pragma Import (C, htonl, "htonl");
begin
   return htonl (Enum_Type'Pos (Value));
end Enum_To_Big_Endian_Unsigned32;


-- file: enum2u32_test.adb - Test Main Program
with Interfaces;
with Enum_To_Big_Endian_Unsigned32;

procedure Enum2U32_Test is

   type Color_T is (Red, Green, Blue);

   function To_U32 is new Enum_To_Big_Endian_Unsigned32 (Color_T);

   Result : Interfaces.Unsigned_32 := To_U32 (Green);

begin
   -- application code ...
   null;
end;