Compilare: user.cpp: In function ‘bool win(char)’: user.cpp:95:22: warning: unused variable ‘blank’ [-Wunused-variable] int on_something,blank; ^ user.cpp: In function ‘bool has_move(char)’: user.cpp:154:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ user.cpp: In function ‘std::string run()’: user.cpp:266:1: warning: control reaches end of non-void function [-Wreturn-type] } ^