Re: [Boost-users] boost:any/boost::variant for integral/floating type

 struct get_min_visitor    : public boost::static_visitor<>    {    template <typename T>      T operator()(T & i) const        {        return std::numeric_limits<T>::min();        }    };

You have to pass the result type as an argument to static_visitor template. Maybe you meant something like this: //... AttributeValue(int i) : Value(i) {} AttributeValue(double d) : Value(d) {} // etc... struct get_min_visitor : public boost::static_visitor<AttributeValue> { template <typename T> AttributeValue operator()(const T &) const { return std::numeric_limits<T>::min(); } };