We can extend this solution like this: int main() { std::string my_text = "My text for encoding!"; std::string encoded_text; boost::base64().encode( my_text, std::back_inserter( encoded_text ) ); // Or like this: // boost::base64().encode( my_text, encoded_text ); // or: // boost::base64().encode( my_text.begin() // , my_text.end() // , encoded_text ); std::string my_text_again; boost::base64().decode( encoded_text, std::back_inserter( my_text_again ) ); // Or like this: // boost::base64().decode( encoded_text.begin() // , encoded_text.end() // , std::back_inserter( my_text_again ) ); } So developer can choose the interface he likes. All technical details, of course, will be discussed... - Denis