codif.cpp: In function 'std::string conv(std::vector<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > >)': codif.cpp:40: warning: comparison between signed and unsigned integer expressions codif.cpp: In function 'void back(int, std::vector<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > >)': codif.cpp:56: warning: comparison between signed and unsigned integer expressions codif.cpp:62: warning: comparison between signed and unsigned integer expressions codif.cpp: In function 'int main()': codif.cpp:84: warning: comparison between signed and unsigned integer expressions