Compilare: user.cpp: In function ‘void polish_form()’: user.cpp:53:19: warning: unused variable ‘aux2’ [-Wunused-variable] struct Elem aux, aux2, vf; ^ user.cpp:54:6: warning: unused variable ‘op1’ [-Wunused-variable] int op1, op2; ^ user.cpp:54:11: warning: unused variable ‘op2’ [-Wunused-variable] int op1, op2; ^ user.cpp: In function ‘int main()’: user.cpp:120:6: warning: unused variable ‘i’ [-Wunused-variable] int i; ^ user.cpp: In function ‘int priority(char)’: user.cpp:27:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ user.cpp: In function ‘int eval(char)’: user.cpp:42:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ user.cpp: In function ‘void polish_form()’: user.cpp:92:25: warning: ‘vf.Elem::prio’ may be used uninitialized in this function [-Wmaybe-uninitialized] while(!stk.empty() && vf.prio >= aux.prio){ ^ user.cpp:63:26: warning: ‘vf.Elem::info’ may be used uninitialized in this function [-Wmaybe-uninitialized] result = eval(vf.info); ^