Re: [boost] [variant] Warning: variadic templates in boost::variant

Subject: Re: [boost] [variant] Warning: variadic templates in boost::variant
From: Larry Evans (cppljevans_at_[hidden])
Date: 2013-12-10 16:54:13

On 12/10/13 15:35, Larry Evans wrote:
[snip]
>
> Hi Matt,
>
> I'm trying to understand how you arrive at the static_visitor.  Since
> the set of bounded types in the variant is a result of
> metaprogramming, I'm guessing that the static_visitor would also have
> to be the result of some metaprogramming.  Otherwise I can't figure
> out how it could be done.  I'm guessing that you use some sort of
> inheritance for each bounded type.
   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Should be:

   inheritance for the operator() member function
   for each bounded type.

IOW.

template<typname Head, typename... Tail>
class my_visitor
: public my_visitor<Tail...>
{
public:
     int operator()(Head&) const
     ;
};

template<>
class my_visitor
: public static_visitor<int>
{
};

> Is that right?
>
> -regards,
> Larry
>
>
>
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