Re: [boost] Re: unions

From: E. Gladyshev (egladysh_at_[hidden])
Date: 2003-10-07 04:17:20

--- Eric Friedman <ebf_at_[hidden]> wrote:

[...]
> In short, then, there's no theoretical reason to treat T1 specially, but 
> it seemed to me a good compromise. Indeed, the optimization is usable 
> even in generic contexts, e.g.:
> 
>    template <typename U1, ..., typename UN>
>    class my_class
>    {
>      variant< boost::empty, U1, ..., UN > var_;
>    };
> 
> or if using a MPL-compatible typesequence:
> 
>    template <typename Types>
>    class my_class
>    {
>      variant<
>          typename mpl::push_front< Types, boost::empty >::type
>        > var_;
>    };

It is not a good solution. Should my_class wrapper duplicate 
all variant interfaces?

Eugene

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