transfer.cpp: In function 'std::vector<int> get_attachment(std::vector<int>)':
transfer.cpp:6:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
6 | for (int i = 0; i < source.size(); i++)
| ~~^~~~~~~~~~~~~~~
transfer.cpp:15:6: warning: unused variable 'bi' [-Wunused-variable]
15 | int bi = 0;
| ^~
transfer.cpp: In function 'std::vector<int> retrieve(std::vector<int>)':
transfer.cpp:36:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
36 | for (int i = 255; i < data.size() - 1; i++)
| ~~^~~~~~~~~~~~~~~~~
transfer.cpp:38:27: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
38 | x2 += data[i] * (1 << i - 255);
| ~~^~~~~