Compilare: user.cpp: In member function ‘const int number::operator+=(number&)’: user.cpp:37:5: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In member function ‘const int number::operator=(number&)’: user.cpp:41:5: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In function ‘int main()’: user.cpp:47:26: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d", &n); ^