Compilare: user.cpp: In constructor ‘NrMare::NrMare(std::string)’: user.cpp:18:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < s.size(); ++i) ^ user.cpp: In member function ‘bool NrMare::operator+=(NrMare&)’: user.cpp:23:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0; i<cifre.size() || i < x.cifre.size() || c; i++, c/=10) ^ user.cpp:23:54: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0; i<cifre.size() || i < x.cifre.size() || c; i++, c/=10) ^ user.cpp:24:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i < cifre.size()) ^ user.cpp:28:5: warning: no return statement in function returning non-void [-Wreturn-type] } ^