Class is not a class template

Question

i get the error : class is not a class template .Any idea why?

template<class T>
class nod{
          friend class lista<T>;
protected:
          T info;
          nod<T> *urm,*prec;
        };

Answer 1

lista is not known yet at this point in the code. So of course the compiler doesn't think it's a template class. You need to forward declare it with its template arguments. See also: How to forward declare a C++ template class?