Compilare: user.cpp: In function ‘fractie convert(std::__cxx11::string)’: user.cpp:31:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < s.length(); ++i){ ~~^~~~~~~~~~~~ user.cpp:47:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = posperiod; i < s.length(); ++i) ~~^~~~~~~~~~~~ user.cpp:62:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = posvirgule; i < s.length(); ++i) ~~^~~~~~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:122:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < primes.size(); ++j) ~~^~~~~~~~~~~~~~~