Function dispatch

include/chaiscript/dispatchkit/proxy_functions.hpp:936–984

    /// function is found or throw dispatch_error if no matching function is found
    template<typename Funcs>
      Boxed_Value dispatch(const Funcs &funcs,
          const std::vector<Boxed_Value> &plist, const Type_Conversions_State &t_conversions)
      {
        std::vector<std::pair<size_t, const Proxy_Function_Base *>> ordered_funcs;
        ordered_funcs.reserve(funcs.size());

        for (const auto &func : funcs)
        {
          const auto arity = func->get_arity();

          if (arity == -1)
          {
            ordered_funcs.emplace_back(plist.size(), func.get());
          } else if (arity == static_cast<int>(plist.size())) {
            size_t numdiffs = 0;
            for (size_t i = 0; i < plist.size(); ++i)
            {
              if (!func->get_param_types()[i+1].bare_equal(plist[i].get_type_info()))
              {
                ++numdiffs;
              }
            }
            ordered_funcs.emplace_back(numdiffs, func.get());
          }
        }


        for (size_t i = 0; i <= plist.size(); ++i)
        {
          for (const auto &func : ordered_funcs )
          {
            try {
              if (func.first == i && (i == 0 || func.second->filter(plist, t_conversions)))
              {
                return (*(func.second))(plist, t_conversions);
              }
            } catch (const exception::bad_boxed_cast &) {
              //parameter failed to cast, try again
            } catch (const exception::arity_error &) {
              //invalid num params, try again
            } catch (const exception::guard_error &) {
              //guard failed to allow the function to execute,
              //try again
            }
          }
        }

        return detail::dispatch_with_conversions(ordered_funcs.cbegin(), ordered_funcs.cend(), plist, t_conversions, funcs);
      }
  }
}