Can I use boost::enable_if on a member function?

Question

I\'m writing a template class, and I want to allow an additional method to exist only for a certain template type. Currently the method exists for all template types, but c

Answer 1

Yes, this is possible, but not with the class template parameter directly. boost::enable_if can only be used with a template parameter on the method itself. So, with a little typedef usage:

template
class MyClass  : public BASE
{
public:
  typedef Utility2 util;

  typename T& operator() (const Utility1& foo);

  template
  typename boost::enable_if, T>::type const &
  operator() (const U& foo) const;
};

This works, because Utility2 can only be created from a certain BASE type. So if the BASE type is something else, the const version of operator() won't exist.

So, it's a very minor thing. It doesn't gain me much. But it was neat to do.