/in/foo.cc: In function 'void extendBigInt(BigInt&, int)':
/in/foo.cc:161:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     if (num.size() < len) {
         ~~~~~~~~~~~^~~~~
/in/foo.cc: In function 'void calculatePi(int)':
/in/foo.cc:228:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         if (i < pi_sum.size()) {
             ~~^~~~~~~~~~~~~~~