Variadic Switch

Several years back I found an interesting question on Reddit. Essentially the author asks why there is no way to expand a pack into a sequence of case labels followed by a statement. It was illustrated with the following imaginary syntax: ```c++ template <class Visitor, class Variant, std::size_t … Is> auto visit_impl(Visitor visitor, Variant && variant, std::index_sequence) { auto i = variant.index(); switch (i) { (case Is: return visitor(get(variant));)... } }