Method parse

demo_example/http/http_request.hpp:47–56

    /// the input has been consumed.
    template <typename InputIterator>
    std::tuple<result_type, InputIterator> parse(request& req,
                                                 InputIterator begin,
                                                 InputIterator end) {
        while (begin != end) {
            result_type result = consume(req, *begin++);
            if (result == good || result == bad)
                return std::make_tuple(result, begin);
        }
        return std::make_tuple(indeterminate, begin);
    }

private:
    /// Handle the next character of input.