sir5.cpp: In function `std::string transform(std::basic_string<char, std::char_traits<char>, std::allocator<char> >)': sir5.cpp:19: warning: comparison between signed and unsigned integer expressions sir5.cpp:22: warning: comparison between signed and unsigned integer expressions sir5.cpp: In function `int main()': sir5.cpp:80: warning: comparison between signed and unsigned integer expressions sir5.cpp:100: warning: comparison between signed and unsigned integer expressions