Compilare: user.cpp: In function ‘void polish_form()’: user.cpp:47:19: warning: unused variable ‘aux2’ [-Wunused-variable] struct Elem aux, aux2, vf; ^ user.cpp: In function ‘int main()’: user.cpp:133:6: 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, int, int)’: user.cpp:36:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ user.cpp: In function ‘void polish_form()’: user.cpp:30:2: warning: ‘vf.Elem::info’ may be used uninitialized in this function [-Wmaybe-uninitialized] switch(op){ ^ user.cpp:47:25: note: ‘vf.Elem::info’ was declared here struct Elem aux, aux2, vf; ^ user.cpp:92:25: warning: ‘vf.Elem::prio’ may be used uninitialized in this function [-Wmaybe-uninitialized] while(!stk.empty() && vf.prio >= aux.prio){ ^