lexical_cast made optimizations for some types (such as `std::string`) to achieve better performance. But, from my experience, it seems that lexical_cast does not make any optimization for `boost::iterator_range<std::string::iterator>`. Is there any plan to add optimization for such iterator ranges? Currently, - `lexical_cast<int>(std::string(iter_rng.begin(), iter_rng.end()))` is faster than `lexical_cast<int>(iter_rng)`. - Assuming it is safe to use `std::atoi`, `std::atoi(&iter_rng.front())` is faster than both of the above two methods. (`iter_rng` is an instance of `boost::iterator_range<std::string::iterator>`.) Regards, Michel