Hi,

I'm using FPC 2.6.2 and {advancedrecords}.
The compiler shows a warning when I use a record variable. IMO this is a bug because record variables need not be initialized, right?

project1.lpr(20,3) Warning: Variable "r" does not seem to be initialized
=== BEGIN ===
program Project1;
{$mode objfpc}{$H+}
{$modeswitch advancedrecords}
type
  TMyRec = record
    procedure Print;
  end;
procedure TMyRec.Print;
begin
  writeln('foo');
end;
var
  r: TMyRec;
begin
  r.Print;
end.
=== END ===

Marcos Douglas

Managed types (strings, interfaces, dynamic arrays) inside a record will have a valid value (Nil), but other values will he garbage. The compiler does not check whether a record contains any non-managed fields before generating the warning.

Regards,
Sven

Some new syntax has to be introduced to avoid the warning. Something like:

type
  TMyRec = record
    record procedure Print;
  end;
record procedure TMyRec.Print;
begin
  writeln('foo');
end;

thanks,
Dmitry

P.S. this message is not as straight forward as it might seem.

Am 31.12.2013 00:48 schrieb "Dmitry Boyarintsev" <

We don't need a new syntax for something that already works:

=== code begin ===

type
 TMyRec = record
    class procedure Print; static;
  end;
class procedure TMyRec.Print;
begin
 writeln('foo');
end;
begin
  TMyRec.Print;
end.

=== code end ===

Regards,
Sven

Ok. But is this will be "corrected" in the next version? Because if won't, I can not see sense to use it.
The structure that does same but does not have this problem is the object type. But is it used yet? I think Delphi make it deprecated, right?

Talking about Delphi, it has the same problem with warnings on records?

Thanks,
Marcos Douglas

Yes, but if is need to use like this, is better using the sintaxe Unit.Function...
I would like to use a variable (short name) but without initialize it (Constructor).

Regards,
Marcos Douglas

It seems that this was already corrected at least in trunk as a test with 2.7.1 does not show a warning anymore. I don't know whether the corresponding fix was merged to 2.6.3 though (I assume "no" by default for compiler changes though).

The structure that does same but does not have this problem is the object type. But is it used yet? I think Delphi make it deprecated, right?

What do you mean "But is it used yet?"? And yes, Borland, Codegear, Embarcadero, whoever decided that "object" is deprecated in Delphi in FPC however they are still fully working and also benefit from newer features here and then (mostly because "object" shares a lot of code with "class" and "interface").

Talking about Delphi, it has the same problem with warnings on records?

Didn't test that.

Regards,
Sven

Depends on the preference of the developer I'd say. I personally prefer the usage of "typename.method" instead of "unit.function" for example.

Regards,
Sven

If was corrected in 2.7.1 is enough for me.

Is recommended to use it or FPC team recommends to use "record" instead?

So, maybe is more useful to use object type instead record type to group functions.

Thanks,
Marcos Douglas

Me too, but without warnings. ;-)

I prefer to group procedures/functions (utilities) inside object/record (in classes too, of course) instead using unit.function sintaxe. IMHO the code is more readable and organized.

Regards,
Marcos Douglas

The methods for records were introduced for Delphi compatibility, so they are rather young compared to objects (which are still used here and then inside the compiler for example, because most code is from a time when records could not have methods). In contrast to objects they however provide support for operator overloads (you need to use these if you want to use overloaded operators inside a generic) and they can have a variant part. Objects however support inheritance if the need arises.

Depends on the use case and preference. See above.

Regards,
Sven