13 Templates [temp]

13.8 Name resolution [temp.res]

13.8.3 Non-dependent names [temp.nondep]

Non-dependent names used in a template definition are found using the usual name lookup and bound at the point they are used.
void g(double);
void h();

template<class T> class Z {
  void f() {
    g(1);           // calls g(double)
    h++;            // ill-formed: cannot increment function; this could be diagnosed
                    // either here or at the point of instantiation

void g(int);        // not in scope at the point of the template definition, not considered for the call g(1)
— end example