Unions destructors and GC precision

[Jonathan M Davis]

On Wednesday, August 15, 2012 07:02:25 Simen Kjaeraas wrote:
> On Tue, 14 Aug 2012 22:32:58 +0200, Andrei Alexandrescu
> 
> <SeeWebsiteForEmail at erdani.org> wrote:
> > On 8/14/12 3:25 PM, bearophile wrote:
> >> D2 doesn't give you that restriction, and when an union goes out of
> > 
> >> scope it calls the destructors of all its fields:
> > That's pretty surprising. "Major bug" doesn't begin to describe it.
> > 
> > Unions should call no constructors and no destructors.
> 
> That means the default case is unsafe. Should it also be an error
> (or at least a warning) for a union containing types with destructors
> or complex constructors not to have a defined constructor/destructor?

I wouldn't expect unions to be considered @safe in the first place. You're 
potentially reintrepreting one type as another with them. And I would expect 
that anything in them is in the same boat that anything initialized to void 
is. e.g.

Type var = void;

- Jonathan M Davis