Compilare: user.cpp: In function ‘bool getval()’: user.cpp:35:15: warning: array subscript has type ‘char’ [-Wchar-subscripts] t=val[a[i]]^t;cuv();is(); ^ user.cpp: In function ‘int main()’: user.cpp:46:14: warning: array subscript has type ‘char’ [-Wchar-subscripts] val[o]=!val[o]; ^ user.cpp:46:22: warning: array subscript has type ‘char’ [-Wchar-subscripts] val[o]=!val[o]; ^ user.cpp: In function ‘bool eval()’: user.cpp:25:1: warning: control reaches end of non-void function [-Wreturn-type] } ^