[fpc-pascal] Case in Record

[Vincent Snijders]

Jürgen Hestermann schreef:
> Therefore, there is absolutly no difference between
> 
> TFigure = record
>           X : TShapeList;
>           case TShapeList of
>              Rectangle: (Height, Width: Real);
>              Triangle: (Side1, Side2, Angle: Real);
>              Circle: (Radius: Real);
>              Ellipse, Other: ();
>              end;
> 
> and
> 
> TFigure = record
>           case X : TShapeList of
>              Rectangle: (Height, Width: Real);
>              Triangle: (Side1, Side2, Angle: Real);
>              Circle: (Radius: Real);
>              Ellipse, Other: ();
>              end;
> 
> It ends up in the same record and also the programmer does not see any 
> difference. He can store whatever he wants in X in both cases. It has no 
> influences on the variants.

IIRC, there is a difference. With the second declaration the compiler can add a 
run-time check that the correct memebrs are accessed based on the value of X.

Unfortunately, I cannot find the compiler switch.

Vincent