Re: [boost] Re: Re: Proposal --- A type-safe union

From: Douglas Gregor (gregod_at_[hidden])
Date: 2002-06-13 06:58:12

On Thursday 13 June 2002 02:18 am, Andrei Alexandrescu wrote:
> What I also believe, in contradiction with some participants, is that
> Variant should use typelists. If not, then Variant will factionally
> develop its own little typelist facility (as some other libraries in
> boost do today) and this doesn't work very nicely.

For the interface or just the implementation? I don't see how we could avoid 
typelists in the implementation, but we don't need them in the interface. We 
have a choice between:

template<typename T1, typename T2 = unused2, ..., typename TN = unused3>
class variant;

and

template<typename Types>
class variant;

        Doug