The following code example is taken from the book
C++ Templates - The Complete Guide, 2nd Edition
by David Vandevoorde, Nicolai M. Josuttis, and Douglas Gregor,
Addison-Wesley, 2017
© Copyright David Vandevoorde, Nicolai M. Josuttis, Douglas Gregor 2017
template<int N>
class X {
public:
using I = int;
void f(int) {
}
};
template<int N>
void fppm(void (X<N>::*p)(typename X<N>::I));
int main()
{
fppm(&X<33>::f); // fine: N deduced to be 33
}