lexical_cast - Serbipunk/notes GitHub Wiki
https://www.boost.org/doc/libs/1_65_1/doc/html/boost_lexical_cast.html
int represented as a std::string, or vice-versa
C and C++ libraries offer a number of facilities for performing such conversions
The lexical_cast function template offers a convenient and consistent form for supporting common conversions to and from arbitrary types when they are represented as text.
specs performance:
https://www.boost.org/doc/libs/1_65_1/doc/html/boost_lexical_cast/performance.html