template2.c

this is a gcc file, you can download it and learn its usetility, for further detail please look at t

// { dg-do compile }
// { dg-options -O2 }

template<class T> struct O {
  O(T *p) : q(p) { }
  T *q;
};
struct W {
  virtual ~W();
};
struct S : public W {
  S (int *);
};
W *bar(int);
S::S (int *x)
{
  for (int *p = x; *p; p++)
    O<W> i (bar (*p));
}