Question

I wrote code that looked like the following:

template<typename CocoaWidget>
class Widget : boost::noncopyable
{
private:
  CocoaWidget* mCocoaWidget;

public:
  Widget()
  {
    mCocoaWidget = [[CocoaWidget alloc] init];
  }

  // ...
};

class Button : Widget<NSButton>
{
  // ...
};

But that doesn’t work, because Mac Dev Center says:

Objective-C classes, protocols, and
categories cannot be declared inside a
C++ template

So what shall I do now best?

Answer 1

Are you sure you can’t do this (have you tried)?

The quote from Mac Dev Center says you can’t declare an Objective-C class inside a template. What you’re doing, however, is merely declaring a pointer to an Objective-C object inside a template — quite a different thing, and I don’t see a reason why it shouldn’t be allowed (though I have never tried).