vector<USBCardDevice> found_cards = find_all_cards();
unsigned ret = found_cards.size();
for (size_t i = 0; i < found_cards.size(); ++i) {
vector<USBCardDevice> found_cards = find_all_cards();
unsigned ret = found_cards.size();
for (size_t i = 0; i < found_cards.size(); ++i) {