Hello devs.

Please explain why the next example does not compiles with a message: "Error: Wrong type "Array Of Const" in array constructor"?

program Project1;
{$mode delphi}{$H+}
function g_object_dosomething(AObject: Pointer; args: array of const):
Boolean; cdecl; external 'test.dll';
type
   TGObject = object
      function DoSomething(args: array of const): Boolean; stdcall;
   end;
function TGObject.DoSomething(args: array of const): Boolean; stdcall;
begin
   g_object_dosomething(@self, args);
end;
begin
end.

If I change "cdecl" to "stdcall" in g_object_dosomething then it compiles with no error.

For me it is strange. Should developer care about internal compiler representation of an "array of const" for different conventions? Imo this is a compiler task.

I've checked the same on delphi XE and there it compiles.

So whether this is 1)a bug 2)unimplemented feature 3)desired compiler behavior?

Best regards,
Paul Ishenin.

It's more that even though both are called "array of const", they are completely different things. They also don't support the same types.

You could say it is an unimplemented feature, but implementing it would require a lot of assembler code that's different for every architecture (and in some cases also for different OSes, since not all OSes use the same ABI and the ABI defines how C varargs must be passed). It is not a bug since the error message is given on purpose.

Jonas

Jonas Maebe wrote

It's more that even though both are called "array of const", they are completely different things. They also don't support the same types.

Perhaps varargs-compatible parameter type should be called something else then?

Both backwards and Delphi compatibility stand in the way of that.

Jonas