auto print = [](auto const& view) {
   for (std::cout << "{"; const auto element : view)
       std::cout << element;
   std::cout << "}";
};

struct Splitter {
   constexpr Splitter(char c): c(c) {}

   constexpr int Class() const {
       if (c == ' ' || c == '.' || c == ',') return 1;
       if (c >= '0' && c <= '9') return 2;
       return 0;
   }

   constexpr bool operator==(Splitter rhs) const {
       return Class() == rhs.Class();
   }

   char c;
};

int main()
{
   constexpr std::string_view hello { "Some string123,to tokenize.last" };
   std::ranges::for_each(
       hello | std::ranges::views::split(
           std::ranges::single_view<Splitter>{std::in_place, ' '}
       ),
       print);
   std::cout << '\n';
   std::ranges::for_each(
       hello | std::ranges::views::split(
           std::ranges::single_view<Splitter>{std::in_place, '0'}
       ),
       print);
}