/in/foo.cc: In function 'void ConvHelper::fft(cd*, int, int)':
/in/foo.cc:119:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             if (n != brev.size()) {
                 ~~^~~~~~~~~~~~~~
/in/foo.cc: In member function 'UnsignedDigit UnsignedDigit::move(int) const':
/in/foo.cc:221:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         if (-k >= digits.size())
             ~~~^~~~~~~~~~~~~~~~
/in/foo.cc: In member function 'UnsignedDigit UnsignedDigit::operator*(const UnsignedDigit&) const':
/in/foo.cc:288:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i + 1 < tmp.size(); ++i) {
                     ~~~~~~^~~~~~~~~~~~
/in/foo.cc: In constructor 'UnsignedDigit::UnsignedDigit(std::__cxx11::string)':
/in/foo.cc:375:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i < str.size(); ++i) {
                     ~~^~~~~~~~~~~~