Re: %union errors that shouldn't be there

[Hans Aberg]

At 10:39 +0100 2005/03/22, Laurence Finston wrote:
> On Mon, 21 Mar 2005, Hans Aberg wrote:
>
> >  They should be OK in C++, as pointers do not have non-trival
> >  con-/de-structors. The compiler needs to see a declaration of the
> >  name as a type, though, before it sees the pointer.
>
> If I remember correctly, it has to do with the size of the objects not
> being known at the time the `union' declaration is compiled.  I'm not
> sure, but I think I tested this once and discovered, somewhat to my
> surprise, that using pointers in the `union' didn't work, either.  When I
> get a chance, I'll check this carefully.

With unions, the problem is, if con-/de-structors are non-trivial, 
that it is impossible to know which ones to apply and when. The union 
does not contain any type information which field is selected. If one 
adds that, unions with non-trivial con-/de-Structors would be 
possible.
--
  Hans Aberg