transfer.cpp: In function 'std::vector<int> get_attachment(std::vector<int>)':
transfer.cpp:8:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    8 |     for (int j = 0; (1 << j) < source.size(); ++j) {
      |                     ~~~~~~~~~^~~~~~~~~~~~~~~
transfer.cpp:10:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   10 |         for (int i = 0; i < source.size(); ++i) {
      |                         ~~^~~~~~~~~~~~~~~
transfer.cpp: In function 'std::vector<int> retrieve(std::vector<int>)':
transfer.cpp:25:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   25 |     for (int i = 0; i < data.size() - (data.size() < 255 ? 7 : 9); ++i) {
      |                     ~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
transfer.cpp:32:11: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   32 |         i < data.size() - 1; ++i) {
      |         ~~^~~~~~~~~~~~~~~~~
transfer.cpp:42:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   42 |     for (int j = 0; (1 << j) < source.size(); ++j) {
      |                     ~~~~~~~~~^~~~~~~~~~~~~~~
transfer.cpp:44:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   44 |         for (int i = 0; i < source.size(); ++i) {
      |                         ~~^~~~~~~~~~~~~~~