Compilare: user.cpp: In function ‘void polish_form()’: user.cpp:49:19: warning: unused variable ‘aux2’ [-Wunused-variable] struct Elem aux, aux2, vf; ^ user.cpp: In function ‘void evaluate()’: user.cpp:112:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < vpol.size() - 1; i++){ ^ user.cpp:111:16: warning: unused variable ‘op’ [-Wunused-variable] int op1, op2, op; ^ user.cpp: In function ‘int main()’: user.cpp:143:6: warning: unused variable ‘i’ [-Wunused-variable] int i; ^ user.cpp: In function ‘int priority(char)’: user.cpp:29:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ user.cpp: In function ‘int integer(char)’: user.cpp:38:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ user.cpp: In function ‘void polish_form()’: user.cpp:99:21: warning: ‘vf.Elem::info’ may be used uninitialized in this function [-Wmaybe-uninitialized] while(!stk.empty() && vf.info != '('){ ^ user.cpp:86:25: warning: ‘vf.Elem::prio’ may be used uninitialized in this function [-Wmaybe-uninitialized] while(!stk.empty() && vf.prio >= aux.prio){ ^