BorlandTalk.com

Adem · Guest

Hi,

I am thinking of using a structure such as below to
facilitate conversion from one basic type to other(s).

TGenericConverter = packed record
case Byte of
0: (
LongWord0: LongWord;
);
1: (
Integer0: Integer;
Integer1: Integer;
);
2: (
Word0: Word;
Word1: Word;
Word2: Word;
Word3: Word;
);
3: (
Byte0: Byte;
Byte1: Byte;
Byte2: Byte;
Byte3: Byte;
Byte4: Byte;
Byte5: Byte;
Byte6: Byte;
Byte7: Byte;
);
4: (
Integers: array[0..1] of Integer;
);
5: (
Words: array[0..3] of Word;
);
6: (
Bytes: array[0..7] of Byte;
);
end;

The attractive part is, as long as my data is 8-bytes max,
I seem to be able to access its various segments easily. i.e.

<snippet>
var
Value1: TGenericConverter;
begin
Value1.LongWord0 := 12345678;
if Value1.Byte4 then begin
{so something here}
end;

if Value1.Word1 then begin
{so something here}
end;
end;
</snippet>

Looks attractive.

Yet, the fact that I haven't seen much use of this sort of thing
makes me suspect that there may be more than meets the eye (or, I).

What are the pros and cons.

I'd appreciate your views.

Cheers,
Adem

Hrvoje Brozovic · Guest

Adem wrote:

Adem · Guest

Hrvoje Brozovic wrote:

Adem · Guest

Lee_Nover wrote:

Primoz Gabrijelcic · Guest

FYI, Sysutils.pas defines:

WordRec = packed record
case Integer of
0: (Lo, Hi: Byte);
1: (Bytes: array [0..1] of Byte);
end;

LongRec = packed record
case Integer of
0: (Lo, Hi: Word);
1: (Words: array [0..1] of Word);
2: (Bytes: array [0..3] of Byte);
end;

Int64Rec = packed record
case Integer of
0: (Lo, Hi: Cardinal);
1: (Cardinals: array [0..1] of Cardinal);
2: (Words: array [0..3] of Word);
3: (Bytes: array [0..7] of Byte);
end;

And that's been with us for a looooong time...

Read the source, Luke!

--Primoz

Lee_Nover · Guest

Hrvoje Brozovic · Guest

Adem wrote:

Kristofer Skaug · Guest

Adem wrote:

Adem · Guest

Kristofer Skaug wrote:

Adem · Guest

Hrvoje Brozovic wrote:

Adem · Guest

Primoz Gabrijelcic wrote:

Hrvoje Brozovic · Guest

Adem wrote: