Compilare: user.cpp: In function ‘void split_tokens(std::string&)’: user.cpp:30:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (end = 0; end < line.size(); ++end) { ^ user.cpp: In function ‘void parse(int&, Entry*)’: user.cpp:53:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (i < tokens.size()) { ^ user.cpp: In function ‘void sort_and_print(Entry*, std::string, std::ostream&)’: user.cpp:91:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < root->files.size(); ++i) { ^