Compilare: user.cpp: In constructor ‘nod::nod(long int, char)’: user.cpp:30:10: warning: ‘nod::val’ will be initialized after [-Wreorder] long val; ^ user.cpp:29:10: warning: ‘char nod::op’ [-Wreorder] char op; ^ user.cpp:31:5: warning: when initialized here [-Wreorder] nod(long _val=0,char _op=' '):val(_val),op(_op){}; ^ user.cpp: In function ‘int main()’: user.cpp:90:10: warning: unused variable ‘rez’ [-Wunused-variable] long rez=0,nr=0; ^ user.cpp: In function ‘long int calculus(long int, long int, char)’: user.cpp:62:1: warning: control reaches end of non-void function [-Wreturn-type] } ^