- template <typename I1, typename I2>
- struct apply : I1::template equal_to<I1, I2> {};
+ template <typename It1, typename It2, typename Tag1, typename Tag2>
+ struct dispatch : mpl::false_ {};
+
+ template <typename It1, typename It2, typename Tag>
+ struct dispatch<It1, It2, Tag, Tag> // same tag
+ : It1::template equal_to<It1, It2>
+ {};
+
+ template<typename It1, typename It2>
+ struct apply : dispatch<It1, It2,
+ typename It1::fusion_tag, typename It2::fusion_tag>
+ {};