On 07/01/19 20:12, Mattias Gaertner via fpc-devel wrote:
On Mon, 7 Jan 2019 19:24:53 +0100
Jonas Maebe <jo...@freepascal.org> wrote:
Object class methods do have a self parameter. If an object has a
vmt, the object class methods get this vmt pointer passed as self
parameter. Otherwise they get nil as self parameter. Kylix does not
support calling object class methods through tobjecttype.classmethod
either, which is indeed kind of strange.
Thanks. I learned something new.
But what is this Self?
TBird = object
class procedure DoIt; virtual;
end;
class procedure TBird.DoIt;
var
o: TBird;
begin
o:=Self;
// Error: Incompatible types: got "Class Of TBird" expected "TBird"
end;
But "Class Of TBird" does not exist in FPC, does it?
No, it does not. The compiler currently unconditionally creates a
classrefdef for the self parameter, regardless of whether it's a class
or object type. This should probably changed into void pointer for
objects. Although even Kylix prints "Error: Incompatible types: "TBird"
and "Class Reference", so it seems we're also Delphi-compatible here :)
Jonas
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