/in/foo.cc: In function 'int main()':
/in/foo.cc:78:22: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   78 |         if (s.size() != total_len) {
      |             ~~~~~~~~~^~~~~~~~~~~~